Forensic Examination and Report Writing

4 Forensic Examination and Report Writing



The locus


In the context of forensic investigation, the ‘locus’ is the term used to describe the site or scene where the event occurred. Examination of the locus can help to place the incident in perspective and adds to interpretation of the post-mortem findings. However, unlike medical forensic pathologists, the veterinary pathologist is rarely invited to attend at the locus. More usually, the police or other investigators remove the cadaver from the crime scene and submit it for examination some time later. There may be little alternative in cases of wildlife crime where the incidents often occur in remote areas.


Nevertheless, it is advantageous if the veterinarian has the opportunity to examine the scene and gain at first hand an insight to the location and to the position in which the animal was discovered. Important issues, such as evidence of struggling, attempted escape or restraint, can be assessed at this time. When more than one animal has died or been killed, a site visit can be helpful in determining whether the deaths occurred at the same time or sequentially. Examination of the locus may also assist in placing the incident in a particular timeframe by observation of environmental clues associated with the body. The last two points are of relevance in, for example, investigations of suspected neglect of farm animals where cadavers are present in different pens or fields.


There are three basic types of loci:


1. Incident, death and discovery at one site, e.g. a collie dog is found drowned in a disused quarry with a rope and heavy weight around its neck.

2. Incident at one site, death and discovery at another, e.g. a hen harrier is fatally wounded by gunshot at one site but manages to fly to another location before dying and subsequently being discovered.

3. Incident and death at one site, discovery at another, e.g. a red deer stag is shot and killed by a poacher who then transports the body to a venison dealer’s premises where the body is discovered following a tip-off.


General forensic procedure


The establishment of protocols for medicolegal investigations in veterinary medicine introduces a degree of standardisation that fosters objectivity and also encourages thoroughness. The use of a standardised protocol means that each case follows a routine, which, if adhered to, results in reliable documentation. The protocol should also include routines for radiography, photography, sample collection, labelling and storage of specimens. This may sound complicated but, once the system is set up and running, it becomes a routine that is easily followed.


No single set of protocols suits all circumstances, and each veterinarian, or group of veterinarians, should develop procedures that fit with their working practices. Best practice guidelines include:


• Maintenance of the chain of evidence by the provision of a receipt for the specimen when it is delivered to the laboratory or practice. (Evidence labels attached to the specimens should be signed at the time of receipt.)

• Recording of the specimen in the ‘daybook’ or computer system, and labelling of the specimen with a unique laboratory reference number.

• Creation of a document file, at the first opportunity, to record relevant details such as name of the person or organisation submitting the specimen (including any paperwork or labels accompanying but not attached to the cadaver), and contact details (e.g. telephone number and postal address).

• Availability of suitable, secure, storage facilities for the types of specimen being submitted. For example, small birds with delicate limb bones that are readily fractured post mortem should be stored separately from bigger, heavier specimens.

• Prevention of cross-contamination from one specimen to another by suitable leakproof storage bags/containers.

• Maintenance of a register of samples being placed in fridges or freezers dedicated to forensic work.

• Establishment of a routine for identifying, dating and signing radiographs.


Necropsy procedure



Preliminary considerations



The necropsy form


It is extremely easy, during a long and complicated necropsy, to forget to record details of an organ or sample. Consequently, the use of standard forms is recommended to prompt the pathologist to weigh and measure as required, to examine all systems and to take the necessary samples. Ideally, there should be a system of checking or corroboration that the procedures are being followed.



Receipt


When cadavers or specimens (including items such as dog collars or rings/jesses from birds) are received, a comprehensive history should be noted on the submission form. If, for reasons of confidentiality in sensitive cases, details of the circumstances have been withheld by the police, a note of this should be recorded. Similarly, comments such as ‘received frozen’ or ‘in rigor mortis’ should also be recorded, because questions may be raised about the state of the cadaver many months later.


A note should be kept as to the date and time of receipt, and what happened to the body immediately after receipt, i.e. was the body immediately necropsied, or placed in a cold store or in a freezer for examination later.



Public health factors


Some thought should be given to public health considerations and the possibility of disease, including exotic disease, before beginning the post-mortem examination. For example, imported psittacines transported in inadequate containers may well have died from hyperthermia or stress, but initial handling of these cadavers should take into account possible risks from diseases such as avian influenza. The use of a safety cabinet may be appropriate to safeguard the health of laboratory personnel.



Identification of particular species


The agency or person submitting a cadaver or specimen often identifies them in general terms (e.g. ‘owl’ rather than ‘tawny owl’ or ‘short-eared owl’) and it is advisable that the pathologist also uses the general term. This avoids any difficulties caused when different witnesses give different species names for the same specimen. It is also important to remember that in most cases, the veterinarian’s expertise lies in the field of pathology, not taxonomy, so it is wise to avoid the possibility of making identifications that may cause one to look foolish later. However, if the veterinarian considers that the animal may have been wrongly identified then the submitting agency should be contacted and arrangements made for a formal identification by an appropriate expert. The expert should then attach an additional label bearing the correct species name.



Labels


Labels carrying the laboratory reference number of the cadaver are crucial to the maintenance of the chain of evidence and should be durable. Self-adhesive strips (12.7 mm wide) of industrial-quality, laboratory labelling tape, that is unaffected by freezing, with the laboratory reference number printed in black letters on a white background or white letters on a blue background, are easily read, convenient and permanent. These strips can be placed around the leg above the carpus or hock joint, and can also be attached to other exhibits that form part of the evidence (e.g. a blood-stained baseball bat).


Some specimens may arrive with a paper or card evidence label that has been attached by the prosecuting authority or reporting agency. These labels, which are usually attached to the specimen by cord or string, can be protected from damage and contamination during the post-mortem examination by slipping them into self-sealing plastic bags and closing the bag mouth tightly around the cord/string. These evidence labels must be retained and are preferably left attached.



Removal of coverings


Any coverings around the cadaver (e.g. plastic bags, blankets, towels, papers or other materials) should be removed carefully one by one and listed. Identification marks or writing on the coverings should be recorded and any postage or transportation labels attached to the covering retained. Leakage of fluids should also be noted. The coverings may be malodorous and/or blood-stained, and it is not usually practical to retain them, but a careful search should be made for small objects enclosed within them, such as previously used submitting-agency identification tags (which have been removed), collars, leads or dogs’ toys. These objects must be recorded and retained.



Body weight and length


After all coverings are removed, the body is weighed. The weighing machine used should be validated as accurate by regular calibration. The length of the body is then measured, a simple and convenient measurement being the length of the body from the back of the head to the base of the tail. (Weight and body size are particularly important in cases of neglect where the animal may have been deprived of nutrition.)

Related posts:

  1. Fundamentals of Animal Abuse
  2. Introduction
  3. Asphyxia and Drowning
  4. Thermal Injuries

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Oct 7, 2016 | Posted by in GENERAL | Comments Off on Forensic Examination and Report Writing

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