Examination of the Deceased Victim and Forensic Toxicology
______ inch square piece of tissue should be submitted.
1
Climatological data should be recorded at the scene as well as obtained from the weather station to the scene for the previous ___-____ weeks or longer.
1-2
What factors can impact the rate of cooling (algor mortis)?
BCS, position of body, type of surface body is on, presence of a covering, if body becomes wet, weather, density of hair coat
What is algor mortis?
Cooling of the body after death, from normal internal body temp to the surrounding environmental temp
__________ Mortis is the pooling of blood due to gravity in dependent body sites after the heart has stopped beating.
Livor
How do you collect blowfly eggs?
break off small piece size of dime, break in half and place one half in 75% ethyl alcohol and other half in larval rearing pouch, small piece of beef/pork liver should be placed inside as feeding substrate, place inside plastic container for shipment and label everything
All photographs must be ________________ in court.
authenticated
What are the two types of decomposition?
autolysis and putrefaction
What is the difference between autolysis and putrefaction?
autolysis causes the breakdown of tissues and organs by enzymes, putrefaction involves bacteria and fermentation
How do you distinguish lividity vs. bruising?
bruised area will have diffuse hemorrhage into the soft tissue while lividity is confined to the blood vessels
How do you differentiate between bruising and livor mortis?
bruised area will have diffuse hemorrhage into the soft tissues, lividity is confined to blood vessels
What type of camera should be used for photographs?
digital
How should dry and wet fecal samples be stored?
dried feces in paper container, wet feces in leak proof container and immediately frozen
When does the investigation begin for determining non accidental injury?
begin when exam findings do not match initial history
Livor mortis: If fixation has occurred and pressure is applied, the area will not __________.
blanch
Do not ________ or clean the tooth/bone samples.
bleach
What should you not do to bone samples?
bleach or clean them
What factor surrounding an animals death is liver mortis helpful at determining?
body position/if the body was moved
What external and internal factors can cause rigor mortis to set in faster or slower?
exercise prior to death, violent struggle, convulsions and high body temp can cause to set in faster; cold body may stop or slow down formation an disappearance; poisons that cause convulsions can speed up; animals with decreased glycogen levels (starved animals) causes faster onset and shorter duration
Areas of insect activity on a deceased body start around the _________ and is followed by the urogenital-anal area, and then around any __________.
head, wounds
Samples of internal organs should be collected for what diagnostic tests during a necropsy?
histopathology, microbiology, virology, parasitology, clinical pathology, and toxicology
Determining the PMI interval
insects have forensic value based on what they consume and feed on, specific drugs can alter the rate of larval development, it is possible to test the gut contents of maggots for DNA
How reliable is the change (algor mortis)?
it is most accurate 24 hrs after death but must be considered an estimate to be placed in the context of other findings
Collecting maggots: Look for the __________/__________ larvae as they hatched first/were first eggs laid.
largest, oldest
Specific drugs can alter the rate of ____________ development so the presence of drugs should be well documented for the entomologists benefit.
larval
___________ with protective backers can be used to pick up hair, dust, fibers, pollen and similar trace evidence.
lifters
The body should be examined under alternate _________ source which detects bodily fluids and fibers.
light
What is the goal of analyzing trace evidence?
look for evidence that can recreate the event, link suspect to victim, victim to scene, or suspect to scene
Forensic necropsy is performed in cases where there are ____________ circumstances
suspicious
What is the wet-dry technique?
swab area with sterile swab moistened with distilled water, roll a dry sterile swab in the moistened area to absorb rehydrated fluid
How are buccal swabs taken?
swab placed inside cheek and swirled 10 times, no food or water 20 minutes prior, two swabs from each animal, air dry briefly and place in paper envelope/swab box
How is evidence collected if it is fluid? A dried fluid?
take sample with a sterile swab, use wet-dry technique for dried fluid (swab area with sterile swab moistened with water then use a dry sterile swab to absorb rehydrated fluid)
What should you do if the evidence is fluid?
take the sample with a sterile swab
What can be used in the absence of lifters?
tape
The time of colonization is dependent on _________________ and may be influenced by rainfall, sun exposure, and snow.
temperatures
What is the time of colonization dependent on?
temperatures
Give a pro and con of finding trace evidence on an animal rather than a human.
Pro - fur can hold embedded trace evidence like human hair and there is an entire body to which it can stick to Con - evidence can be easily dislodged and lost, depending on density and length of fur
Foundation for forensic entomology use that can be determined by analyzing climate data include:
1) time of colonization 2) rate of growth 3) stages of insect succession
There should be no food or water _____ minutes prior to sample collection by buccal swab.
20
Muscles, organs, hide, and fixed tissues may be used for DNA unless _____ hours postmortem or the body has been significantly decomposed.
72
Clear close-ups of important findings should be enlarged to ____x____ for the court.
8x10
Photographs should always be taken at a ______ degree angle to the area of interest.
90
Rigor mortis occurs in the depletion of ________, causing muscle proteins actin and myosin to stay locked together until decomposition.
ATP
Why is trace evidence on the feet easily lost?
If the animal was mobile or licked their feet, it will be easily lost
Define chain of custody
a process of documentation so the evidence is accounted for at all times
What is the chain of custody?
a process of documentation so the evidence is accounted for at all times
What is adipocere?
a yellowish-white, greasy, wax-like substance that forms from the fat of the body
Where should you start on the body for a necropsy?
abdomen
What factors accelerate or slow down decomposition?
accelerated by heat, slowed down by cold, freezing can stop process (autolysis), accelerated in animals who are septic prior to death (putrefaction),
Where should the control swab be taken from?
adjacent to the area of interest
Blowflies colonize a body __________ death so therefore the time of death would have occurred on or slightly before the date and time of initial colonization.
after
What should samples of accelerants be stored in?
airtight, nonporous containers to prevent evaporation
Forensic entomology definition
analysis of insects for legal cases with main purpose of determining the post mortem interval (time of death)
What should be noted in the access log?
any transfer of the evidence to another location should be noted in the evidence log with time, date, and signatures of the sender and recipient
What is evidence? Give definition and two examples.
anything collected from a crime scene, two examples are the animal and any photographs taken
What situation will livor mortis not occur?
areas pressed against a firm surface
What is forensic necropsy used to determine?
cause of death, manner of death, any contributing causes, and time of death
Temperature data should be documented at every __________ in animal's environment and location.
change
What are all the aspects that must be considered when determining nonaccidental injury?
circumstances surrounding injury/death, owner's explanation, environmental conditions, medical history
What must be considered when investigating a potential nonaccidental injury?
circumstances surrounding injury/death, owner's explanation, environmental conditions, medical history
Trace evidence can also be found on:
collars, leashes, bowls, toys, dog house, carriers and anything else linked to the animal
Control samples of the victim's fur should be taken for potential _________________ to the scene of the crime.
comparisons
Insects have forensic value based on what they _____________ and feed on as they may be analyzed for ___________ that were present in the body at the time of death.
consume, drugs
What characterizes algor mortis?
cooling of body after death, from normal internal body temp to surrounding environmental temp
Trace evidence analysis: neither persons nor animals can visit a _________________ without leaving something of themselves behind, or taking something with them.
crime scene
What should evidence be labeled with?
date, time, and description of the item
A photograph must never be ________________ , regardless of the quality.
deleted
What factors dictate the approach to necropsy?
depends on injuries or allegations to the animal
What happens 60-72 hours after decomposition?
eyes may bulge, tongue protrudes from mouth, skin color is pale greenish/black, red colored fluid will drain from mouth and nose, surface tissues begin to dry and get a leathery texture
What parts of the body should be examined for trace evidence?
face, lips, teeth, legs and feet
What are some sources of DNA?
fresh blood, buccal swabs, bones and teeth, hair and hide, feces, muscle, saliva, semen, urine
What are accepted sources of DNA?
fresh or dried blood, buccal swabs, bones and teeth, hair and hide, feces, muscle, saliva, semen, urine,
Fresh tissue should be ___________ in an airtight container and shopped overnight with a cold pack to the lab.
frozen
Moist DNA samples that are collected should be tightly sealed, labeled and __________.
frozen
The body should be touched and moved as little as possible and never be ______________.
frozen
What types of photographs should be taken?
general shots of the animal, right/left sides, rear and dorsal views, clear close ups of findings, photographs taken at 90 degree angle to area of interest
What happens 24-36 hours after decomposition?
greenish discoloration of abdomen, formation of bacterial gas which can cause bloating, marbling (green-black coloration)
__________ residue particles can be collected using lifters to determined concentration, patterns, and for analysis of the particles.
gunshot
How do you collect maggots?
look for largest/oldest larvae since they were there first, temp/time should be recorded, sample of collected maggots should be preserved at the scene, boil maggots for 5 minutes to kill and blanch them, transfer to 75-80% isopropyl alcohol
How frequently should an animals temp be taken to determine rate or cooling (algor mortis)?
multiple times over 3-6hr period
What characterizes rigor mortis?
muscle contraction that immobilizes the joints in the body
What is rigor mortis?
muscle contraction that immobilizes the joints of the body
Evidence is less likely to be present under the _________ of an animal.
nails
What is the belief behind trace evidence?
neither persons nor animals can visit a crime scene without leaving something of themselves behind, or taking something with them
Clean latex or _________ gloves should be worn during DNA collection.
nitrile
Can rigor mortis appear in conjunction with decomposition? If so, when?
no, it disappears with decomposition
Why does rigor mortis occur?
occurs in the depletion of ATP, causing actin and myosin to stay locked together until decomposition
Evidence bags should be _________ instead of ________ to avoid moisture build up.
paper, plastic
Hair or fibers should be placed in _____________ fold paper.
pharmacist's
Collection of entomological evidence: presence of an empty ________ indicates a complete blowfly life cycle has occurred.
pupa
Algor mortis: Heat is lost through conduction, convection, and ____________
radiation
Full body ____________ should be taken before the necropsy.
radiographs
What is a cadaveric spasm?
rare case where rigor is spontaneous after death
Collection of Entomological Evidence: casings are often mistaken for ________ feces.
rat
How should you take an animals temperature?
rectally or in the liver after a small incision
What is a common characteristic of abuse?
repetitive injuries
What order does rigor disappear in?
same order as formation
What should always be the first step for a necropsy?
scan for a microchip
Nails should be __________ over paper/jar to collect potential trace evidence.
scraped
Photographs should start with general ___________ of the animal, including the animal ID number.
shots
How should the collected tissue samples during a necropsy be handled?
should be kept in 10% buffered formalin to preserve tissue,
Any transfer of evidence to another location should be noted in the evidence log with time, date, and ______________ of the sender and recipient.
signatures
High temperatures ________________ rigor mortis.
speed up
What is forensic entomology?
the analysis of insects for legal cases with the main purpose of helping determine the post-mortem interval (time of death)
If there is fixed lividity in nondependent areas of the body, what does this indicate?
the body has been moved after death
What can be determined by analyzing climate data?
time of colonization, rate of growth, stages of insect succession
What should be documented regarding collection of insects?
time, temperature, location, presence of unhatched eggs, blowfly egg masses (first photographed) location
Why are paper evidence bags used?
to avoid moisture build up
Fur can hold embedded _________ evidence like human hair, and there is an entire body to which it can stick to.
trace
What should the external exam include?
trace evidence, fluids and evidence of injury, measurements, BCS, presence and location of rigor and lividity, temperature of body, hair coat condition, detectable odors, otoscopic and opthalmoscopic exams, discharge, mucous membranes, genitalia, bones and extremities, feet and nails
What should the external exam include?
trace evidence, measurements, BCS, presence of rigor and lividity, temperature of body, hair coat condition, detectable odors, otoscopic and opthalmoscopic exams, discharges, mucous membranes, bones and extremities, feet and nails, any entomological evidence
What should you do if evidence is wet?
transport in plastic bag for max of 2 hours, allow to dry in clean area, place in paper evidence bag
What tools are used for the collection of trace evidence? Give two examples.
tweezers, lifters, tape, fine toothed comb
Who can collect DNA?
veterinarians, law enforcement, other authorities that can testify
what are the characteristics of liver mortis?
visible in light colored skin and internal body organs; coloration is usually reddish purple to violet
when collecting tape evidence, it should be placed in a box lined with _______ paper.
wax
If the evidence is a dried fluid, use the ____________ technique.
wet-dry
What should be noted outside the exam?
what suspect was wearing, any wounds, what was present at the scene, the different environments the animal may have been kept in prior to exam
What should be noted on the bags kept on the feet?
which foot it was, who removes the bag, and date and time of removal
What should the body be transported in? Should it be saved?
wrap body in white sheet for transport, bag should be examined and saved for evidence
Can rigor mortis reoccur if broken before fully developed?
yes
Should radiographs be taken while still in the body bag?
yes
