Science and Justice 54 (2014) 439–446

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Case review

Bodies in sequestered and non-sequestered aquatic environments: A comparative taphonomic study using decompositional scoring system A. De Donno a,1, C.P. Campobasso b,⁎,1, V. Santoro a, S. Leonardi a, S. Tafuri c, F. Introna a a b c

Section of Legal Medicine, University of Bari, Policlinico, Piazza Giulio Cesare, 70124, Bari Italy Dept. of Medicine and Health Sciences, University of Molise, via De Sanctis, 86100, Campobasso, Italy Dept. of Biomedical Sciences, Section of Hygiene, University of Bari, Piazza Giulio Cesare, 70124, Bari Italy

a r t i c l e

i n f o

Article history: Received 23 April 2014 Received in revised form 4 September 2014 Accepted 20 October 2014 Keywords: Forensic taphonomy Decomposition Post-mortem interval Accumulated degree days Drowning Marine environments

a b s t r a c t The study of decomposition by using accumulated degree days (ADDs) has been suggested not only in terrestrial decay but also for water-related deaths. Previous studies have demonstrated that the accumulation of thermal energy as a function of the post-mortem submersion interval (PMSI) can be derived from a descriptive decompositional scoring system (DSS). In order to verify how useful can the total aquatic decomposition score (TADS) for ADD prediction be, a comparative taphonomic study has been performed between two series of bodies: 16 corpses found floating in shallower waters with a presumptive PMSI from 3 to 118 days and exposed to water temperatures (Tw) between 10.5 and 20.3 °C approximately equating from a minimum of 46 to 1.392 ADD; 52 bodies, all victims of a single shipwreck, found in sequestered environments and subjected to constant Tw of 4 °C for 210 days approximately equating to 840 ADD. The two series of bodies have revealed different stages of decay and a large DSS variability. In most of bodies, freshly formed adipocere was able to delay the appearance of later decompositional stages explaining why most of the bodies were in relatively good condition. Although promising, the accuracy of the TADS model can be affected by adipocere and animal activity. The TADS model suffers of the same limitations for ADD calculations as they can give a false perception of accuracy due to the complexity of integrating all changing factors affecting human decay in sequestered and non-sequestered marine environments (currents, animal activity, water temperatures, depth of submersion). © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

1. Introduction A primary task of any death investigation is the reliable estimation of the post-mortem interval (PMI) which is the time elapsed between death and the recovery of the body also known as time since death [1]. For bodies in aquatic environment the PMI is also called post-mortem submersion interval (PMSI). In this regard, it is widely accepted that terrestrial decomposition differs from aquatic decomposition [2]. In fact, sea water usually slows up putrefaction [3], mainly because of the cooler aquatic temperatures compared with terrestrial temperatures, the salinity or salt concentration reducing the bacterial action, and the protection from insect and small mammal predators [4,5]. However, aquatic environments can deeply affect the rate of post-mortem decay as well as the preservation/dispersal of bodies submerged commonly exposed to different changing conditions like currents, marine animal activity and, water temperatures which can be considered relatively

⁎ Corresponding author at: Department of Medicine and Health Sciences, University of Molise, via De Sanctis, snc., 86100 Campobasso, Italy. Tel.: +39 0874 404 776; fax: +39 0874 404 778. E-mail addresses: [email protected], [email protected] (C.P. Campobasso). 1 These authors have contributed equally to this paper.

constant depending mainly on depth of submersion [6,7]. Unfortunately, in the forensic context there are only few studies dealing with marine taphonomy and the fate of human remains in aquatic environment [8–12]. In 1972, Payne & King [13] first focused on the soft tissue disappearance and loss of body parts using fetal pigs carcasses submerged. Later, Haglund [8] reported the general pattern of soft tissue disappearance and disarticulation of eleven human remains found submerged in salt water and fresh water, by using a skeletonization scoring system (SSS). The SSS was adopted looking for the regional presence of soft tissue, exposure of bone, and disarticulation at the head, neck, hands, forearms, upper arms, feet, legs, pelvic girdle, and trunk. Using pig models in the marine context, Canadian authors [14–16] observed that most invertebrate faunas are opportunistic scavengers and fed on the remains at all time so that no classic succession of invertebrate species can be determined in contrast with insect colonization in terrestrial environments. In deeper experiments, pig carcasses were skeletonized in less than a month due to animal activity whereas for shallow carcasses the remains were not skeletonized for many weeks [16]. It has been noted [1] that most of the scientific papers dealing with PMI as well as PMSI estimation as case studies on human remains or animal models “have never gained any practical relevance since they do not meet the demands in practice (being precise, reliable and giving an

http://dx.doi.org/10.1016/j.scijus.2014.10.003 1355-0306/© 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

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A. De Donno et al. / Science and Justice 54 (2014) 439–446

immediate result)”. Therefore, a need for validation studies of PMSI estimates based on human decomposition in water environments has also been raised [17,18]. A more quantitative approach and the inclusion of statistics in a science that is primarily descriptive have been proposed [19,20] in order to avoid the common scientific controversy in estimating the PMI and PMSI in forensic practice and/or in courtroom proceedings. In this regard it has been demonstrated that decomposition stages and PMI can be predicted with accuracy from temperature records and that a reliable degree-day index can be developed [20]. In fact, not only in terrestrial decay but also for bodies submerged, the study of decomposition by using accumulated degree days (ADDs) can be useful to estimate the PMSI [18,19], and regression equations have also been calculated. ADDs are a summation of temperatures over time (days) or better the accumulation of thermal energy needed for the chemical and biological reactions of decomposition to take place [21]. Since 1967 a strong correlation between time of immersion, water temperature and signs of decomposition has been demonstrated by Reh [22] as recently reported [23]. ADD can be easily derived from a total aquatic decomposition score (TADS) according to descriptive decompositional scoring system (DSS) provided by Heaton et al. [18] based on forensic cases of human bodies recovered from the U.K. waterways. Although these authors [18] already warned about the effect of adipocere on the accuracy of their model because of delaying the appearance of later decompositional characteristics, the purpose of this comparative taphonomic study is to verify how useful can be the TADS for ADD prediction in two series of bodies submerged in sequestered and non-sequestered aquatic environments. In this regard, several forensic taphonomy researchers [18–21,24–27] have used this method recently with great optimism to account for the variability in the level of decomposition in humans, but none of these researchers have achieved the same levels of correlation and accuracy. 2. Materials and methods A total of 68 human remains cases have been selected based on their marine site of recovery: 16 bodies of the first series were found mostly floating or submerged in shallower sea waters, 52 bodies belonging to the second series were all victims of a single shipwreck, all found in sequestered environments of the relict in deep cold water. 2.1. First Series of bodies 16 human remains belonging to 14 males and 2 females with age range of 19–82 years-old, were recovered in the context of forensic investigations from the southern part of the Adriatic Sea. Selection of bodies was mainly based on details available for each case and, in particular, time interval between when the victim was last seen alive and when it was recovered (presumptive PMSI), average water temperatures and ambient temperatures, body recovery site (floating in shallow water close to land or in high seas, depth of submersion, lying on the beach/coast, etc.), presence and type of clothing. Water temperatures were recorded at body recovery and retrospectively obtained by the archives of sea surface temperatures available on the website of the Royal Netherlands Meteorological Institute (KNMI or Koninklijk Nederlands Instituut Meteorologisch) at the following address http://www.knmi.nl/ datacentrum/satellite_earth_observations/NOAA/archive/. The archives collect datasets of temperatures recorded globally 24 h a day by the Advanced Very High Resolution Radiometer (AVHRR), a sensor carried out on the National Oceanic and Atmospheric Administration's (NOAA's) Polar Orbiting Environmental Satellites (POES). No body parts were included in this series. Most of the bodies shared the same cause of death (drowning) based on autopsy findings (see macroscopic and microscopic aspects of lung as well as the absence of fatal injuries and/or other lethal organ failure) [28]. Only in two cases signs of hypothermia were also associated such as frost erythema, acute gastric erosions (Wischnewsky's spots), acute hemorrhagic pancreatitis, bright red color of blood and lividity, hemorrhages into core muscles like the iliopsoas muscle [29]. All 16

bodies exhibited varying degrees of maceration (from washerwoman's changes in hands and feet to skin slippage), decomposition, and partial skeletonization related to submersion time interval in marine environment and animal aquatic activity. The process of adipocere formation was recognizable from its very initial phase (mostly represented in soft and wet cutaneous and sub-cutaneous tissues with a greasy consistency, and localized mainly at the buttocks and the root of the lower limbs) to its older form (a dry and brittle matrix of tissues fibers, nerves and muscles covering anatomical areas like a thin friable crust with a waxy consistency) with partial or total saponification. For this series of bodies, the presumptive PMSI goes from 3 to 118 days and the water temperatures (Tw) range from 10.5 °C to 20.3 °C equating to ADD values from a minimum of 46.2 (15.4 °C × 3 days) to 1393.6 (11.8 °C × 118 days). Only positive Tw were recorded and therefore used in the ADD calculations. Twelve cases were recovered in the winter months (with Tw b 15.4 °C) and four cases in the warm seasons (with Tw N 15.5 °C). All these details are summarized in Table 1 where bodies have been grouped based on presumptive PMSI and related ADD. In six cases the thermal energy was b200 ADD (PMSI: 3–13 days), in six cases ADD ranged between 200 and 400 (PMSI: 14–31 days), in three cases ADD ranged between 400 and 1.000 (PMSI: 30–64 days) and, only one case showed N 1.000 ADD (PMSI: 118 days).

2.2. Second Series of bodies All the 52 bodies were victims of the Kater Radez wreck occurred on March 13, 1997 in the middle of the Otranto Canal (Adriatic Sea). An Albanian ship trying to land clandestinely on the Southern Italian coast sank following a collision with an Italian Navy patrolling the border. All the passengers in the holds died as the ship was quickly engulfed and settled on the bottom of the sea [30]. The relict was located lying on sandy and muddy sea floor at a depth of 800 m approximately with the help of a Sub-marine Remotely Operated Vehicle (SROV). During the search operations, after four months from the sinking, two bodies completely skeletonized were found: one pretty close to the ship on the sea floor and, the second one at the entrance of the after hold (stern). These two bodies were not included in this study as they were examined by other physicians. After seven months, on 18th October 1997, the boat was rescued and 52 bodies totally (28 females and 24 males) were recovered within the four holds of the relict. Victims were mostly young with 43 individuals less than 35 years old among which 23 children (14 males and 9 females) less than 15 years old. Age assessment was performed according to age group by combined methods (physical, dental, and anthropological examinations) [31–33]. Quite all the bodies were fully and heavy clothed dressing in multiple layers. With great surprise, they were in relatively good state of preservation compared with the previous SROV survey documenting two skeletonized bodies outside the boat three months before. In quite all the 52 bodies recovered after 7 months, soft tissues were still present showing the characteristic ammoniacal odor due to initial adipocere formation. Adipocere mixed with decomposition was visible to the naked eye on most of the covered anatomical areas (chest, abdominal wall, and buttocks mainly) with soft and wet cutaneous and sub-cutaneous tissues. Advanced preskeletonization was represented only in particular anatomical regions (such as head/neck and hands) unprotected by clothing. The 52 bodies exhibited varying degrees of decomposition and partial skeletonization related to the prolonged submersion in marine environment and animal aquatic activity [29]. Among the PM changes, a distinct pink coloration of the teeth was found in only 18 cadavers (13 females and 5 males), corresponding to the 34.6% of the sample [34], and mainly related to body position and the still unclear pathogenesis of this phenomenon [35]. All the 52 bodies shared the same cause of death (drowning), and the same environmental conditions: temperature 4 °C, pressure 81 atm, salinity 35%, oxygen 0.5 ml/l, current velocity 10–15 c/s. Therefore, all bodies were subjected to constant temperatures of 4 °C for 210 days approximately

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Table 1 Series of 16 bodies found while floating in shallow waters and exposed to water temperatures ranging from 10.5 °C to 20.3 °C, grouped based on presumptive PMSI. Case # Sex Age Recovery site

Clothing

PM signs of animal activity

Maceration and adipocere formation

Presumptive Season PMSI (days)

Group A: PMSI 3–14 days (b200 ADD) 7 M 41 Floating in high seas

Fully clothed

Erosions at face and hands

03

Jun

46.2 (15.4 °C)

8

M

19

Floating in high seas

Light clothing



03

Nov

52.8 (17.6 °C)

6

M

31

Fully clothed



03

Aug

60.9 (20.3 °C)

13

M

22

Fully clothed

Erosions at face and hands

06

Nov

101.4 (16.9 °C)

3 11a

M F

33 56

Submerged at depth of 10 m Submerged at depth of 20 m on the beach Floating close to land

Washerwoman's changes in hands and feet Washerwoman's changes in hands and feet Washerwoman's changes in hands and feet Skin slippage at hands and feet

only underwear Fully clothed

Abrasions of the nose Erosions at face and limbs

Skin slippage at hands and feet 13 Skin slippage at hands/feet and face 14

Apr–May Feb–Mar

197.6 (15.2 °C) 198.8 (14.2 °C)

16

Sept

283.2 (17.7 °C)

20

Jan–Feb

210.0 (10.5 °C)

25 27

Dec–Jan Mar

292.5 (11.07 °C) 391.5 (14.5 °C)

30

Mar–Apr

462.0 (15.4 °C)

31

Dec–Jan

362.7 (11.7 °C)

Group B: PMSI 15–31 days (200–500 ADD) 5 M 35 floating in high seas heavy clothing a

M

82

on the coast

15 10

M M

24 27

floating close to land floating in high seas

4

M

37

floating close to land

1

M

23

floating close to land

16

skin slippage at hands/feet and face fully clothed – skin slippage at hands/feet and face fully clothed Erosions at face and limbs Initial adipocere at limbs heavy clothing Pre-skeletonization of skull Initial adipocere at limbs and hands and buttocks sox and shoes Erosions at face and neck Initial adipocere at limbs and abdominal wall scuba diving 3 mm Pre-skeletonization Initial adipocere at limbs long wetsuit face, thorax, hands and abdominal wall

Group C: PMSI 32–65 days (500–1000 ADD) 9 F 24 Floating close to land Only underwear 12

M

38

Floating in high seas

Light clothing

2

M

54

On the beach

Partially clothed

Group D: PMSI N70 days (N1000 ADD) 14 M 42 Floating close to land Heavy clothing a



ADD based on average water T

Pre-skeletonization face, thorax, limbs Pre-skeletonization skull, thorax, limbs Pre-skeletonization skull and limbs

Initial adipocere at limbs, buttocks, abdominal wall Saponification

36

Feb–Mar

522.0 (14.5 °C)

58

Feb–Apr

626.4 (10.8 °C)

Saponification

64

Nov–Jan

960.0 (15.0 °C)

Pre-skeletonization of skull and limbs

Total saponification

118

Dec–Apr

1392.4 (11.8 °C)

In these cases signs of hypothermia were also found.

(seven months) equating to 840 ADD totally considering 0 °C as base temperature [36].

In fact, according to Simmons et al. [21] matching DSS against logADD allows the exponential progression of decomposition to be expressed as a simple linear equation.

2.3. Decompositional Scoring System. 3. Results and discussion The stage of decay showed by each of the 68 bodies recovered from the sequestered and non-sequestered environments has been scored using a semi-quantitative evaluation of decomposition and skeletonization. Each body has been classified based on the state of preservation and PM changes according to the DSS designed by Heaton et al. [18]. This classification has been used in order to produce a TADS with the aim to verify the range of values useful for ADD prediction. The materials used to assign a TADS were mainly written reports as well as photographs taken by the forensic pathologists for the victims of the wreck while visual inspection and photographs for most of the I series of bodies. Therefore, a score has been assigned to each descriptive change of decomposition showed by three main anatomical regions (head/neck, trunk and limbs) separately, as different areas do not necessarily display the same aspects of decay [37]. The scores of three anatomical regions (head/neck, trunk and limbs) are grouped in Table 2. In scoring the human remains, particular attention has been paid to the regional presence of soft tissue, exposure of bone, and disarticulation. According to the DSS, the scores for each stage of decomposition range from 1 to 8 for the face/neck and torso, up to 9 for the limbs, producing a TADS, which can vary from a minimum of 3 to a maximum of 25 points. The assessment was made by two examiners, separately and at different times. Regression analysis for TADS against log10ADD predicted and ADD calculated based on water and air temperatures has been performed using STAT MP11. A p-value b 0.05 has been considered as significant.

The final scores assigned to the study group, according with DSS, are illustrated in Table 3 for sequestered and non-sequestered series of bodies. In both series of bodies, inter-examiner variability was no longer than one score for most of the anatomical regions. Only for a few of assessments not in agreement (a couple of scores for the first series and 6 cases for the sequestered bodies), a re-evaluation was then performed until final correspondence. Most of the 68 victims were in relatively good condition with soft tissues still present as clearly shown by the low frequency of scores 8 and 9 for DSS in sequestered (only 15 cases out of 52 and mainly concentrated at the limbs) and non-sequestered bodies (only the single case of group D showed complete disarticulation of the skull and extensive adipocere formation related to his prolonged PMSI while in other 3 bodies of group C bones of hands and/or feet were beginning to disarticulate). Soft tissues were mostly complete especially at the upper arm, pelvic girdle, and foot, those body parts covered by heavy clothing and footwear. In non-sequestered bodies (Table 3a), scores 4 and 5 were assigned mostly to head/neck and trunk because of maceration with initial skin slippage while scores 6 and 7 were assigned mostly to limbs because of degloving effect with exposure of underlying muscles and tendons. In sequestered bodies (Table 3b), partial or total exposure of bones due to loss of overlying soft tissue was observed mainly at the head/neck region as well as at the hands and wrist, those anatomical

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Table 2 Descriptive stages of decomposition observed in the head/neck, the trunk, and the limbs with assigned aquatic decompositional scores. Modified from Heaton et al., 2010. Score 1 Head/neck: no visible or relevant changes. Trunk: no visible or relevant changes. Limbs: no visible or relevant changes. 2 Head/neck: slight pink discoloration, darkened lips, goose pimpling. Trunk: slight pink discoloration, goose pimpling. Limbs: mild wrinkling of skin on hands and/or feet, possible goose pimpling. 3 Head/neck: reddening of face/neck. Marbling visible on face/neck. Possible early signs of animal activity/predation concentrated on the nose, ears, and lips. Trunk: yellow/green discoloration of the abdomen and upper chest. Marbling. Early decomposition/autolysis of internal organs. Limbs: skin on palms of hands and/or soles of feet becoming white, wrinkled, and thickened. Slight pink discoloration of arms and legs. 4 Head/neck: bloating of the face. Green/black discoloration. Skin beginning to slough off. Trunk: dark/green discoloration of abdomen, mild abdominal bloating. Initial skin slippage. Limbs: skin on palms of hands and/or soles of feet becoming soggy and loose. Marbling of the limbs predominantly on upper arms and legs. 5 Head/neck: head hair beginning to slough off mostly at the front. Brain softening and becoming liquefied. Tissue becoming exposed on face and neck. Green/black discoloration. Trunk: green/purple discoloration, extensive abdominal bloating, tense to touch, swollen scrotum in males, exposure of underlying fat and tissues. Limbs: skin on hands/feet starting to slough off. Yellow/green to green/black discoloration on arms and/or legs. Initial skin slippage on arms and/or legs. 6 Head/neck: bone becoming exposed, concentrated over the orbital, frontal, and parietal regions. Some on the mandible and maxilla. Early adipocere formation. Trunk: black discoloration, bloating becoming softer, initial exposure of internal organs and bones. Limbs: degloving of hands and/or feet — exposing large areas of underlying muscles and tendons. Patchy sloughing of skin on arms and/or legs. 7 Head/neck: more extensive skeletonization on the cranium. Disarticulation of the mandible. Trunk: further loss of tissues and organs, more bone exposed, initial adipocere formation. Limbs: exposure of bones of hands and/or feet. Muscle, tendons, and small areas of bone exposed in lower and/or legs. 8 Head/neck: complete disarticulation of the skull from torso. Extensive adipocere formation. Trunk: complete skeletonization and disarticulation. Limbs: bones of hands and/or feet beginning to disarticulate. Bones of upper arms and/or legs becoming exposed. 9 Limbs: complete skeletonization and disarticulation of limbs.

parts mostly exposed to marine environmental organisms. In fact, in the second series of bodies, scores 6 and 7 were assigned mostly to head/ neck and limbs compared with scores 5 and 6 mostly represented at the torso. In non-sequestered series, maximum score 9 for DSS was never assigned. In the sequestered series, score 9 was assigned only in two cases dealing with complete skeletonization of the forearms and disarticulation of hand/wrist bones. Heavy clothing was able to inhibit the release of the few other disarticulated bones (i.e. mandible, cervical vertebrae, phalanges and other hand bones still attached by ligaments and/or thinly tissue bridges) explaining why there were only a couple of missing body parts and very few complete disarticulation of the skull (4 cases only) in the sequestered series of bodies. In most of the study group, freshly formed adipocere was able to delay the appearance of later decompositional stages as clearly shown by the skin and subcutaneous tissues with an unctuous, waxy consistency producing a characteristic ammoniacal odor. In the sequestered series, initial adipocere formation appeared on most covered areas of the bodies explaining the preservation of body tissues strictly related also with the environmental cold water. In non-sequestered series, only one body showed total saponification (group D) while partial saponification with extensive subcutaneous adipocere was observed in a couple of bodies of group C (PMSI: 32–65 days). In this regard, Heaton et al. [18] already warned about the effect of adipocere on the accuracy of their model. In

fact, the two series of bodies have revealed consistent DSS variability because of the different stages of decay. 3.1. First Series of bodies Despite the small size of this study group, the bodies found floating in shallower waters showed a wide range of TADS values from 7 to 23 (Fig. 1) consistent with the large presumptive PMSI from 3 to 118 days. In particular, TADS from 7 to 14 were assigned to bodies of group A (PMSI: 3–14 days), TADS from 14 to 18 for bodies of group B (PMSI: 15–32 days), TADS from 19 to 21 for bodies of group C (PMSI: 32– 65 days), and finally TADS of 23 to the only one body with PMSI N70 days. For each case, the ADD calculated on average Tw are within the ADD predicted within 95% confidence intervals by the TADS assigned (Table 4). However, the ADD predicted by TADS (according to the regression model by Heaton et al. [18]) show an increasing distance from the ADD based on average Tw with a range from 4 days (group A) to 112 days (group D). The increasing distance seems to be consistent with the increasing PMSI considered from few days up to 4 months. However, worth of mentioning, the distance between ADD predicted by

Table 3 Final scores of the semi-quantitative evaluation according with the decompositional scoring system (DSS): a) for the 16 bodies found in non-sequestered environments, b) for the 52 bodies found in sequestered environments. Scores Selected Regions

N

1

2

3

4

a) Cranium & neck Limbs Trunk

5

16 16 16

– – –

1 – 2

3 3 2

6 1 3

1 4 5

b) Cranium & neck Limbs Trunk

52 52 52

– – –

– – –

– – –

– – 2

6 3 14

6

7

8

9

2 3 2

2 2 2

1 3 –

– – –

21 16 31

21 22 5

4 9 –

– 2 –

Fig. 1. Distribution of 16 victims found in non-sequestered environments by TADS (total aquatic decomposition score).

Table 4 TADS assigned to series of 16 bodies found in aquatic environments while floating in shallow water, grouped based on presumptive PMSI. TADS assigned are related to ADD predicted with 95% confidence intervals based on the regression model by Heaton et al. (2010) and distances from ideal TADS and related ADD predicted. Case #

Presumptive PMSI (days)

ADD based on average air T (Ta)

Distance (D1) from ADD Tw and corresponding days (d)

ADD

ADD

D1

°C

°C

TADS assigned

d

ADD predicted with 95% confidence intervals (min–max)a

ADD

(min-max)

Distance (D2) from ADD Tw and corresponding days (d)

Ideal TADS and distance form TADS assigned

ADD predicted by ideal TADS and distance (D3) from ADD Tw with corresponding days (d)

ADD

D2

d

TADS

−14.21 −29.01 +16.86 −58.39 −58.39 −8.6 −58.2

(b0.9) (b1.6) (N0.8) (b3.4) (b3.4) (b0.5) (b4.0) (0.5–4.0 d)

9 10 10 12 12 14 14

(+1) (+3) (−1) (+3) (+3)

(+1)

46.2 52.8 60.9 101.4 101.4 197.6 198.8

(15.4) (17.6) (20.3) (16.9) (16.9) (15.2) (14.2)

51.3 35.7 75.0 88.8 88.8 195.0 173.6

(17.1) (11.9) (25.0) (14.8) (14.8) (15.0) (12.4)

+5.1 −17.1 +14.1 −12.6 −12.6 −2.6 −25.2

(N0.3) (b0.9) (N0.6) (b0.7) (b0.7) (b0.1) (b1.7) (b1.7 d)

8 7 11 9 9 14 13

31.99 23.79 77.76 43.01 43.01 189.0 140.6

(8.8–110.9) (6.5–82.5) (22.0–270.5) (12.0–149.2) (12.0–149.2) (54.3–665.6) (40.2–492.6)

Group B: PMSI 15–31 days (200–500 ADD) 5 16 283.2 16 20 210.0 15 25 292.5 10 27 391.5 4 30 462.0 1 31 362.7

(17.7) (10.5) (11.7) (14.5) (15.4) (11.7)

307.2 172.0 227.5 332.1 390.0 306.9

(19.2) (08.6) (09.1) (12.3) (13.0) (09.9)

+24.0 −38.0 −65.0 −59.4 −72.0 −55.8

(N1.3) (b3.6) (b5.5) (b4.0) (b4.6) (b4.7) (b5.5 d)

14 14 14 16 15 18

189.0 189.0 189.0 341.7 254.1 617.7

(54.3–665.6) (54.3–665.6) (54.3–665.6) (98.5–1219) (73.1–900.3) (178–2241)

−94.2 −21.0 −103.5 −49.8 −207.9 −255.0

(b5.3) (b2.0) (b8.8) (b3.4) (b13.5) (b21.7) (2–21.7 d)

15 14 15 16 17 16

Group C: PMSI 32–65 days (500–1000 ADD) 9 36 522.0 12 58 626.4 2 64 960.0

(14.5) (10.8) (15.0)

439.2 597.4 806.4

(12.2) (10.3) (12.6)

−82.8 −29.0 −153.6

(b5.7) (b2.6) (b10.2) (b10.2 d)

20 21 19

1117 1501 830.5

(320.4–4135) (429.3–5625) (238.9–3043)

+595.0 +874.6 −129.5

(N41.0) (N80.9) (b8.60) (8.6–80.9 d)

17 18 19

(−3) (−3)

Group D: PMSI N70 days (N1000 ADD) 14 118 1392.4

(11.8)

1132.8

(09.6)

−259.6

(b22) (b22 d)

23

2714

(768.6–10,437)

(N112) (N112 d)

21

(−2)

+1321.6

(+1)

(+1) (+2) (−2)

D3

d

43.01 57.83 57.83 104.50 104.50 189.0 189.0

(−3.19) (+5.03) (−3.07) (+3.10) (+3.10) (−8.60) (−9.80)

b0.2 N0.2 b0.1 N0.1 N0.1 b0.5 b0.6 (b0.6 d)

254.1 189.0 254.1 341.7 459.4 341.7

(−29.10) (−21.00) (−38.40) (−49.80) (−2.60) (−21.0)

b1.6 b2 b3.2 b3.4 b0.1 b1.7 (b3.4 d)

459.4 617.7 830.5

(−62.60) (−8.70) (−129.5)

b4.3 b0.8 b8.6 (b8.6 d)

(−108.6)

b9.2 (b9.2 d)

1501

A. De Donno et al. / Science and Justice 54 (2014) 439–446

Group A: PMSI 3–14 days (b200 ADD) 7 03 8 03 6 03 13 06 13 06 3 13 11 14

ADD based on average water T (Tw)

D1: distance/difference between ADD calculated on average Tw and ADD calculated on average Ta. D2: distance/difference between ADD calculated on average Tw and ADD predicted with 95% confidence intervals by TADS assigned (according with the regression model by Heaton et al., 2010). D3: distance/difference between ADD calculated on average Tw and ADD predicted by ideal TADS (derived from the regression model by Heaton et al., 2010). Ideal TADS: TADS predicting the closest ADD to the real case with 95% confidence intervals (derived from the regression model by Heaton et al., 2010). a Based on the regression model by Heaton et al. (2010).

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TADS and the ADD calculated on average Tw could be significantly much less, in case an ideal TADS has been assigned. In fact, TADS is a number related with qualitative categories of decomposition, and such scoring system introduces a considerable subjectivity into the analysis (partially reduced in this case study by the final agreement of two examiners). In this series of bodies, TADS assigned by the two examiners were no longer, than three scores from the ideal TADS predicting the closest ADD to the real case (Table 4). Considering the ideal TADS, the distance between the predicted ADD and the ADD based on average Tw is no longer than 3.4 days (group B) and 9.2 days (group D) which is quite an acceptable error rate (10% approximately) for bodies with an unknown PMSI. The distance in the assessment of TADS (the difference between actual TADS assigned and ideal TADS derived from the regression model by Heaton et al. [18] and related PMSI) can be explained not only by subjectivity of the examiner in the assessment of DSS but also by the different environmental conditions affecting the general pattern of decay among which cold temperatures, currents, size of the body, clothing, and marine animal activity [8]. Considering the temperatures, Tw were just a little bit warmer than air temperatures (Ta) except for three cases occurred in the warm season (#5, #6, #7). The distance between the ADD based on average Ta and the ADD based on average Tw shows a short range from 1.7 days (group A) to 22 days (group D). The regression models fit the data well for TADS/logADD based on Tw (r2 = 0.88; t = 10.54; p b 0.0001) as shown in Fig. 2. Data developed show an increasing distance between ADD (based on Tw) and ADD (based on Ta) consistent with the increasing PMSI. In fact, the longer the PMSI, the less accurate can the reconstruction of the thermal history [38] and the estimate be. Therefore, when there are no available or reliable Tw, experts should expect that Ta could misclassify their estimates from 12 up to 18% of total ADD, but still pretty close to the ADD predicted by ideal TADS. 3.2. Second Series of bodies Compared with the first series, the sequestered bodies showed a shorter range of TADS from 14 to 24 (Fig. 3). In particular, TADS values from 17 to 21 (predicting ADD from 459 to 1.501) were assigned to the most of the series (40 bodies out of 52). A TADS of 19 was assigned only to 21% of the samples (11 bodies out of 52) whereas 79% of the samples (41 bodies out of 52) showed TADS longer than three scores (compared with the first series of bodies) up to five scores from the ideal TADS. In fact, 19 TADS is the ideal target value for this series of bodies since it is related with 95% confidence interval to 830 ADD, corresponding to 6.9 months at 4 °C. According to the regression model by Heaton et al. [18], TADS of 18–20 related with 95% limits of confidence from 617 to 1.117 ADD respectively (corresponding to 5.1 and 9.3 months of PMSI at 4 °C) were assigned to 53% of the samples (28 bodies out of 52). This finding can be considered a quite good and promising result, pretty close to the temperatures accumulated by our series of bodies with 840

Fig. 2. The regression model resulted from the relationship between TADS assigned and logADD based on average Tw (r2 = 0.88; t = 10.54; p b 0.0001).

Fig. 3. Distribution of 52 victims of the Kater Radez by TADS (total aquatic decomposition score).

ADD totally (4° × 210 days approximately). But 24 cases out of 52 (46% of the sample) were distant from the ideal TADS of 19 showing TADS below 18 and over 20 values predicting ADD just a little bit too far from the target of 840 ADD. Among these 24 bodies, 19 bodies were still within the ADD 95% confidence intervals predicted by the TADS values assigned (from 15 to 23), derived from the regression model by Heaton et al. [18]: the lower 95% confidence intervals were represented by TADS 15 corresponding to 73.1–900.3 ADD and, the upper 95% confidence intervals were represented by TADS 23 corresponding to 768.6–10,437 ADD. Therefore, only three cases out of 52 bodies (5.7%) were indeed totally misclassified: two bodies with TADS 14 (95% confidence interval between 54.3 and 665.6 ADD) and one body with TADS 24 (95% confidence interval from 1027 to 14,235). This result seems to improve the prediction of PMSI by TADS. The regression models fit the data well for TADS versus log/ADD based on average Tw (r2 = 69.2; t = 12.18; p b 0.001) for all sequestered and non-sequestered bodies (Fig. 4). There are several reasons for explaining the wider distance of TADS assigned by the ideal TADS for the sequestered bodies compared with non-sequestered bodies. They include mainly environmental conditions and biological factors other than subjectivity or ability to score decomposition. The pattern and sequence of decomposition observed in the victims of the shipwreck have been already considered unusual for human remains in a marine context for several months [30] but mainly related to the preservation of body tissues caused by the adipocere formation, the sequestered environments where the bodies were found and the heavy clothing they wore. Such closed compartments as well as heavy clothing in multiple layers protected the sequestered and

Fig. 4. The regression model resulted from the relationship between TADS assigned and logADD calculated based on average Tw for all sequestered and non sequestered bodies (r2 = 69.2; t = 12.18; p b 0.001).

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non-sequestered bodies from animal activity of large marine scavengers but not from small fishes, mollusks, and crustaceans like white deep-sea crabs. The feeding activity of these scavengers can explain the mechanism of soft tissue destruction in those body parts (head/neck and hands, in particular) pre-skeletonized in the II series of bodies according to previous reports concerning forensic taphonomy in marine contexts [4,7]. Most of the 52 sequestered bodies showed advanced preskeletonization only in limited amount and in particular anatomical regions (such as head/neck and hands) unprotected by clothing with signs of animal aquatic life. Based on human and animal models [6,8, 14–16] especially the open body orifices on the face (nose, mouth, ears) and the exposed fingers are easily defleshed by marine organisms. Previous case studies inform us that human remains submerged in aquatic environment tend to lose soft tissue primarily at the hands and the facial area because of the thin tissue overlay [6]. Anderson [16] already observed that in shallow waters, there is a very slow tissue loss and cadavers can be still preserved, and in relatively good condition for many weeks compared with bodies submerged at variable depth, which can be skeletonized in less than a month. Therefore, in shallower experiments, biomass loss was mainly due to natural decomposition. But, in peculiar situations like bodies entrapped in sequestered environments or with heavy clothing, soft tissues can persist for a year or more [17] even if submerged in deep waters. This is consistent with the findings of this comparative study where the non-sequestered bodies, floating in shallow waters showed very few signs of PM animal activity (from erosions at face and hands to loss of soft tissues with partial pre-skeletonization of the skull and limbs due to feeding action). Only in one case belonging to group D, the total saponification of the body was associated with the presence of Lepas anatifera. It is a smooth gooseneck barnacle growth on victim's clothing, characterized by its heart-shaped shell, or capitulum, 5 mm in size and bluish-white in color. In this case, the basal diameter of the barnacle (20 mm approximately) gave the evidence of the minimal time the body was exposed to these sessile organisms. L. anatifera needs at least 20 days to get the above size of adhesion of its 5 cm long, flexible peduncle or stalk based on growth rates ranging between 0.2 and 0.5 mm/day at Tw of 12 °C [39–41]. Sorg et al. [17] already emphasized that encrustation or the overgrowth of clothing and skeletal elements by other organisms like sessile invertebrates (barnacles, mollusks and, gastropods) can be a reliable biological clock or an indicator of time passage. 4. Conclusion Usually forensic pathologists and investigators try to evaluate the state of decay in a body to provide an approximate time estimate in order to limit the potential list of missing persons. However, the general pattern of decay observed in water-related deaths is the effect of several circumstances dealing with the body (age, size and clothing) but mainly with environmental factors among which cold temperatures, depths, currents, ecosystems and, aquatic animal activity [4,8]. For example, cold and freezing temperatures can negatively affect the rate of decomposition resulting in a very low correlation between DSS, accumulated temperature and time. Furthermore, it would be at risk to estimate the PMSI based entirely on the accumulation of positive temperatures since the correlation between ADD and the visible stage of decomposition can be large. Therefore, this comparative study reinforces the previous findings that temperature alone is not the only dependant variable for human decomposition. Although promising, the TADS model suffers of the same limitations already emphasized for the ADD calculations in other context like the forensic entomology when applied in the PMI estimation. The false perception of accuracy this model can give is mainly related to the complexity of integrating all factors affecting human decay in water (clothing, marine animal activity, submersion depth, eventually entrapment in sequestered environments or floating in shallow or deep waters, etc.) into a single algorithm other than

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subjectivity in the analysis [42,43]. Determining the PMI and the PMSI is extremely difficult, and precision is impossible, even by using the TADS method, due to a wide biological variability. Every expert should be very careful in the interpretation of the state of preservation of a body, keeping in mind that every case has its own, very specific history. The circumstances of every death investigation are unique, and in our opinion there is no single best algorithm for PMI or PMSI estimation. Acknowledgments The authors gratefully acknowledge all the forensic pathologists, anthropologists and autopsy technicians who worked on bodies at the Section of Legal Medicine, University of Bari. The authors also thank the anonymous reviewers for their relevant and precious comments. References [1] C. Henssge, B. Madea, Estimation of time since death, Forensic Sci. Int. 165 (2007) 182–184. [2] P. Saukko, B. Knight, Knight's Forensic Pathology, 3rd ed. Hodder Arnold, London, UK, 2004. [3] V.J. Di Maio, D. Di Maio, Forensic Pathology, 2nd ed. CRC Press, Boca Raton (FL), 2001. [4] W.C. Rodriguez, Decomposition of buried and submerged bodies, in: W.D. Haglund, M.H. Sorg (Eds.), Forensic Taphonomy, the Post-mortem Fate of Human Remains, CRC Press, Boca Raton, FL, 1997, pp. 459–467. [5] C.P. Campobasso, G. Di Vella, F. Introna, Factors affecting decomposition and Diptera colonization, Forensic Sci. Int. 120 (2001) 18–27. [6] W.D. Haglund, M.H. Sorg, Human remains in water environments, in: W.D. Haglund, M.H. Sorg (Eds.), Advances in Forensic Taphonomy. Method, Theory, and Archaeological Perspectives, CRC Press, Boca Raton, FL, 2002, pp. 201–218. [7] M.H. Sorg, J.H. Dearborn, E.I. Monahan, H.F. Ryan, K.G. Sweeney, E. David, Forensic taphonomy in marine contexts, in: W.D. Haglund, M.H. Sorg (Eds.), Forensic Taphonomy, the Post-mortem Fate of Human Remains, CRC Press, Boca Raton, FL, 1997, pp. 567–604. [8] W.D. Haglund, Disappearance of soft tissue and the distribution of human remains from aqueous environments, J. Forensic Sci. 38 (1993) 806–815. [9] T. Kahana, J. Almog, J. Levy, B.A. Shmeltzer, Y. Spier, J. Hiss, Marine taphonomy: adipocere formation in a series of bodies recovered from a single shipwreck, J. Forensic Sci. 44 (1999) 897–901. [10] S. Boyle, A. Galloway, R.T. Mason, Human aquatic taphonomy in the Monterey Bay area, in: W.D. Haglund, M.H. Sorg (Eds.), Forensic Taphonomy. The Post-mortem Fate of Human Remains, CRC Press, Boca Raton, FL, 1997, pp. 605–614. [11] H.E. Bassett, M.H. Manhein, Fluvial transportation of human remains in the lower Mississippi River, J. Forensic Sci. 47 (2002) 719–724. [12] J.L. Lucas, L.B. Goldfeder, J.R. Gill, Bodies found in the waterways of New York City, J. Forensic Sci. 47 (2002) 137–141. [13] J.A. Payne, E.W. King, Insect succession and decomposition of pig carcasses in water, J. Georgia Entomol. Soc. 7 (1972) 153–162. [14] N.R. Hobischak, G.S. Anderson, Time of submergence using aquatic invertebrate succession and decompositional changes, J. Forensic Sci. 47 (2002) 142–151. [15] G.S. Anderson, N.R. Hobischak, Decomposition of carrion in the marine environment in British Columbia, Canada, Int. J. Legal Med. 118 (2004) 206–209. [16] G.S. Anderson, Decomposition and invertebrate colonization of cadavers in coastal marine environments, in: J. Amendt, C.P. Campobasso, M.L. Goff, M. Grassberger (Eds.), Current Concepts in Forensic Entomology, Springer, 2010, pp. 223–272. [17] G.C. Dickson, R.T.M. Poulter, E.W. Maas, P.K. Probert, J.A. Kieser, Marine bacterial succession as a potential indicator of postmortem submersion interval, Forensic Sci. Int. 209 (2011) 1–10. [18] V. Heaton, A. Lagden, C. Moffatt, T. Simmons, Predicting the post-mortem submersion interval for human remains recovered from UK waterways, J. Forensic Sci. 55 (2010) 302–307. [19] M.S. Megyesi, S.P. Nawrocki, N.H. Haskell, Using accumulated degree-days to estimate the post-mortem interval from decomposed human remains, J. Forensic Sci. 50 (2005) 618–626. [20] J.-P. Michaud, G. Moreau, A statistical approach based on accumulated degree-days to predict decomposition-related processes in forensic studies, J. Forensic Sci. 56 (2011) 229–232. [21] T. Simmons, R.E. Adlam, C. Moffatt, Debugging decomposition data — comparative taphonomic studies and the influence of insects and carcass size on decomposition rate, J. Forensic Sci. 55 (2010) 8–13. [22] H. Reh, Anhaltspunkte fur die estimmung der wasserzeit, Dtsch. Z. Ges. Gerichtl. Med. 59 (1967) 235–245. [23] B. Madea, E. Doberentz, Commentary on V. Heaton, A. Lagden, C. Moffatt, T. Simmons, Predicting the post-mortem submersion interval for human remains recovered from UK waterways, J. Forensic Sci. 55 (2010) 302–307, J. Forensic Sci. 55 (2010) 1666–1667. [24] C.M. Fitgerald, M. Oxenham, Modelling time-since-death in Australian temperate conditions, Aust. J. Forensic Sci. 41 (2009) 27–41. [25] J. Bachmann, T. Simmons, The influence of preburial insect access on the decomposition rate, J. Forensic Sci. 55 (2010) 893–900.

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A. De Donno et al. / Science and Justice 54 (2014) 439–446

[26] A.A. Vass, The elusive universal post-mortem interval formula, Forensic Sci. Int. 204 (2011) 34–40. [27] M.K. Humphreys, E. Panacek, W. Green, E. Albers, Comparison of protocols for measuring and calculating post-mortem submersion intervals for human analogs in fresh waters, J. Forensic Sci. 58 (2013) 513–517. [28] A. Lucci, C.P. Campobasso, A. Cirnelli, G. Lorenzini, A promising microbiological test for the diagnosis of drowning, Forensic Sci. Int. 182 (2008) 20–26. [29] B. Madea, M. Tsokos, B. Preuss, Morphological findings, their pathogenesis and diagnostic value, in: M. Tsokos (Ed.), Forensic Pathology Reviews, vol. 5, Humana Press, Totowa NJ, 2008, pp. 3–21. [30] F. Introna, G. Di Vella, C.P. Campobasso, Migrant deaths and the Kater Radez I wreck: from recovery of the relict to marine taphonomic findings and identification of the victims, Int. J. Legal Med. 127 (2013) 871–879. [31] E. Cunha, E. Baccino, L. Martrille, F. Ramsthaler, J. Prieto, Y. Schuliar, N. Lynnerup, C. Cattaneo, The problem of aging human remains and living individuals: a review, Forensic Sci. Int. 193 (2009) 1–13. [32] F. Introna, C.P. Campobasso, Biological versus legal age of living individual, in: A. Schmitt, E. Cunha, J. Pinheiro (Eds.), Forensic Anthropology and Medicine. Complementary Sciences from Recovery to Cause of Death, Humana Press, Totowa, New Jersey, 2006, pp. 57–82. [33] V. Santoro, A. De Donno, M. Marrone, C.P. Campobasso, F. Introna, Forensic age estimation of living individuals: a retrospective analysis, Forensic Sci. Int. 129 (2009) e1–e4. [34] C.P. Campobasso, G. Di Vella, A. De Donno, V. Santoro, G. Favia, F. Introna, Pink teeth in a series of bodies recovered from a single shipwreck, Am. J. Forensic Med. Pathol. 27 (2006) 313–316.

[35] R. Thapar, S. Choudhry, A. Sinha, R. Bali, D. Shukla, Pink tooth phenomenon: an enigma? J. Forensic Legal Med. 20 (2013) 912–914. [36] A.A. Vass, W.M. Bass, J. Wolt, J. Foss, J. Ammons, Time since death determinations of human cadavers using soil solution, J. Forensic Sci. 37 (1992) 1236–1253. [37] R.E. Adlam, T. Simmons, The effect of repeated physical disturbance on soft tissue decomposition—are taphonomic studies an accurate reflection of decomposition? J. Forensic Sci. 52 (2007) 1007–1014. [38] A.R. Moritz, Classical mistakes in forensic pathology, Am. J. Clin. Pathol. 26 (1956) 1383–1397. [39] F. Evans, Growth and maturity of the barnacles Lepas anatifera, Nature 4644 (1958) 1245–1246. [40] H. Goldberg, J.W. Zahradnik, The feasibility of the gooseneck barnacle Lepas anatifera as a candidate for mariculture, J. Shellfish Res. 4 (1984) 110–111. [41] D.T. Anderson, Barnacles. Structure, Function, Development and Evolution, Chapman & Hall, London, 1994. [42] J. Amendt, C.S. Richard, C.P. Campobasso, R. Zehner, M.J.R. Hall, Forensic entomology: applications and limitations, Forensic Sci. Med. Pathol. 4 (2011) 379–392. [43] M.H. Villet, C.S. Richards, J.M. Midgley, Contemporary precision, bias and accuracy of minimum post-mortem intervals estimated using development of carrion-feeding insects, in: J. Amendt, C.P. Campobasso, M.L. Goff, M. Grassberger (Eds.), Current Concepts in Forensic Entomology, Springer, Dordrecht, 2010, pp. 109–137.

Bodies in sequestered and non-sequestered aquatic environments: a comparative taphonomic study using decompositional scoring system.

The study of decomposition by using accumulated degree days (ADDs) has been suggested not only in terrestrial decay but also for water-related deaths...
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