post mortem 'bruises'

Burke et al (1998) describe a case of post mortem blood extravasation simulating an ante-mortem bruise. They noted that the body had been lying in a dependant position (head/ face down), and that the 'bruising' was found within the loose subcutaneous tissues around the face and neck.

Prinsloo and Gordon (1951) described artefactual extravasation of blood into the anterior neck structures at autopsy, resembling traumatic bruises, and recommended a layered in-situ approach to the neck dissection.

Post mortem lividity ('hypostasis') may sometimes be difficult to distinguish from bruising, and where there is doubt about a potentially significant injury, the area of skin may be incised and sampled for microscopic examination.

marks caused by predation

American cockroach

Source: Wikimedia Commons

Post mortem scavenging of the body by a variety of fauna.

For example, ants can cause superficial linear marks, sometimes associated with considerable haemorrhage, whilst cockroaches can produce deeper injuries with a deep brown colour, well demarcated edges and may be confused with abrasions on the neck made during manual strangulation attempts.

Bodies recovered from water may show marks and damage caused by crustaceans and fish, for example. Exposed areas may be 'nibbled' giving rise to circular marks (crustaceans) or sharp edged marks (crabs).

Carrion birds and scavengers can result in unusual patterns of damage post mortem, with beak marks being misinterpreted as stab-like injuries or shotgun wounds, for example. Crows have been noted to cause 'fraying' of tendon, muscle and nerve fibres at joints (Asamura et al 2004).

Bodies of pet owners dying at home are often scavenged post mortem by their hungry pet - dogs and cats attacking exposed soft tissues such as the mouth and nose. The resulting marks are said to have crenated edges, and underlying bone may be marked (Rutty 2001).

Similarly, rodents are attracted to exposed areas, including the eyes, and commonly, the hands. Tsokos et al (1999) described the morphology of soft tissue wounds caused by post mortem rodent predation, noting that clothed as well as unclothed bodies may be similarly affected;

• Appearance of injuries - circular with crater-like hollow defects
• Injury margins
  • irregular edges, finely scalloped and serrated
  • circumscribed 1-2mm intervals within the wound edges
  • protruding indentations up to 5mm
  • focal distinct parallel cutaneous lacerations (artefacts from the biting action of the upper and lower pairs of incisors)
• Preferential location on body
  • exposed and unprotected parts of the body (face, hands)
  • moist parts of the body (eyelids, nose, mouth)
• Characteristically gnaw all soft tissue off from one area at a time (down to tendons and bone)

They also note that predation can occur indoors as well as outdoors, and that scene examiners should search for evidence of rodent activity or nesting in the vicinity of the body, including evidence of droppings and grease-marks etc.

'Sargasso', by Bonni Reid

lesions that simulate gunshot wounds

There are lesions, injuries and artefacts that resemble gunshot wounds, and Prahlow and McClain (1997 pp. 121-125, 2001 pp. 206-213) have described some of these in detail.

Lesions that have been found to simulate gunshot wounds:

• Animal/ Insect activity
• Insect larvae activity
• Fire ant bite marks
• Wounds caused by another mechanism
  • Ice pick stab wounds (imitating shotgun pellet wounds)
  • Imprint mark from stone pressed into skin
  • Some stab wounds/ lacerations
  • Blunt force trauma from a vehicle part in an RTC (Road traffic collision)
• Wounds caused by or during therapeutic intervention
  • Incised wounds inflicted whilst medics gained venous access (imitating exit wounds)
  • Surgical drainage tube sites (after their removal)
  • Sternotomy wire penetration of skin during CPR
  • Tracheostomy site
• Other
  • Sites of trocar insertion during embalming
    •  

Trochar

Source: Wikipedia

resuscitation-related artefacts

Although abrasions may be found around the skin of the mouth and jaw, cheeks and nose, they are not thought to be encountered around the neck, simulating manual strangulation (Leadbeatter 2001).

Defibrillator 'burns' can frequently be found on the anterior chest wall, and there may be bruising over the front of the chest, particularly over the sternum.

Underlying bone and visceral injury are also frequently discovered, and a full discussion of this topic has been made by Leadbeatter (2001) and Darok (2004).

Cardiopump

Source: Flikr

Active compression-decompression cardiopulmonary resuscitation techniques, using, for example the CardioPump® can give rise to typical marks on the skin and injuries, including a reddish ring on the skin over the sternum and sternal fractures.

mimics of non-accidental injury in children

Source: Adapted from Evans 2001

references

• Asamura H, Takayanagi K, Ota M, Kobayashi K, Fukushima H (2004), 'Unusual characteristic patterns of post mortem injuries', J Forensic Sci 49(3):592-4
• Burke MP, Olumbe AK, Opeskin K (1998), 'Postmortem extravasation of blood potentially simulating antemortem bruising', Am J Forensic Med Pathol 19(1):46-49
• Darok M (2004), 'Injuries resulting from resuscitation procedures', Chapter 13 In: Forensic Pathology Reviews Volume 1', Tsokos M (Ed), Humana Press Inc, Totowa New Jersey
• Evans M-J (2001), 'Mimics of non-accidental injury in children', Chapter 6 In: Rutty GN (Ed), 'Essentials of autopsy practice', Vol. 1 Springer, London
• Prinsloo AI, Gordon I (1951), 'Post-mortem dissection artefacts of the neck - their differentiation from ante-mortem bruises', S A Medical Journal 25(21):358-361
• Leadbeatter S (2001), 'Resuscitation injuries', Chapter 3 In: Rutty GN (Ed), 'Essentials of autopsy practice', Vol. 1 Springer, London
• Rutty GN (2001), 'Post-mortem changes and artefacts', Chapter 4 In: Rutty GN (Ed), 'Essentials of autopsy practice', Vol. 1 Springer, London
• Tsokos M, Matschke J, Gehl A et al (1999), 'Skin and soft tissue artifacts due to postmortem damage caused by rodents', Forensic Science International 104:47-57