I don't know how many other schools offer this subject, but hopefully, these notes help someone out!
Forensic ScienceDefinitionsForensic ScienceThe scientific method of gathering and examining evidence relating to a crime and matters under legal investigation.
Forensic PsychologyForensic psychology applies psychology to legal matters and the criminal justice system.
Crime SceneAny physical location where a crime has occurred or is suspected of occurring.
AnthropologyRecovery and identification of skeletal remains.
EntomologyCollection and study of insects, particularly larvae and maggots to determine the time of death.
GeologyCollection and study of soil and mineral evidence.
OdontologyStudy of dental remains and bite marks.
SerologyCollection and study of DNA in blood, semen, saliva, vaginal fluids (and other bodily liquids).
DactologyCollection, study and identification of human fingerprints.
PathologyConduction of autopsies.
PodiatryCollection and examination of footprints (and shoe prints).
PsychologyThe study of characteristics of perpetrators.
ChemistryCollection and study of accelerants and gunshot residue.
ToxicologyThe study of the influence of drugs and poisons on the body.
Crime ScenesWhen arriving at a crime scene, certain procedures must be followed. When an officer arrives at a scene they ensure that no one is in immediate danger before securing the scene. Evidence is photographed before being bagged and collected.
Types of EvidenceTestimonial EvidenceOral or written statements given to police as well as court testimony by people who witnessed an event.
Physical EvidenceAny material items that would be present at a crime scene.
Trace EvidencePhysical evidence found in small but measurable amounts.
Trace EvidenceLocard's Exchange Principle is that: "Every contact leaves a trace." Trace evidence is evidence that is found in small but measurable amounts.
BloodBlood TypesType A: A antigen, B antibody
Type B: B antigen, A antibody
Type AB: A and B antigens, no antibodies
Type O: no antigens, A and B antibodies
Blood Spatter Analysis- Blood falling vertically forms circular marks with serrated edges.
- Blood falling from a moving object will hit a surface at an angle, forming a spatter with smaller spots showing the direction of the movement.
- Spines can help to make a rough estimate of the height a spatter was dropped from.
- The shape of the blood spatters can help estimate the steepness from which the blood fell.
- Castoffs are droplets of blood released behind a moving weapon.
FingerprintsFingerprints are the marks left behind when someone touches an object with their finger. They can be collected by dusting (if on non-porous surfaces) or on absorbent surfaces they can be collected using iodine.
There are three main patterns: arches, whorls and loops.
65%- loops
30%- whorls
5%- arches
Patent PrintsPrints that are clearly visible such as those made by hands covered in blood, soot or dirt.
Latent PrintsPatterns made by oil soot and dirt on the ridges of fingertips. They are not clearly visible and must be developed in some way so that they can be seen.
Exemplar Prints(also known as exclusion prints)
Deliberately collected from a suspect to be compared to prints from the crime scene.
Handwriting AnalysisHandwriting analysis can be useful in cases involving cheques, letters, wills and suicide notes. Comparisons are made by looking at twelve different factors including spaces, dotting & crossing, and fancy loops & swirls.
Dental RecordsTeeth can change with time meaning that dental records aren't always helpful. However, teeth are resistant to fire so records can be used to help identify a body.
Bullets and BallisticsBullet MatchingEach gun has a distinct pattern (rifling or striations), meaning that scratch marks on a bullet are like 'fingerprint' from the gun that fired it. If a gun is suspected of being used in a crime, another bullet can be fired from it and the scratch marks can be compared. This is known as test firing and bullet matching.
Gunshot ResidueGunpowder in bullets usually contains traces of barium, lead and antimony. If someone is arrested for gun crimes their hands will be swabbed and analysed using atomic absorption spectrometry. If traces of these elements are found, they generally indicate that someone has been firing a gun.
Test FiringTest firing is used when a bullet found at a crime scene needs to be matched to a gun. Guns suspected of being used will have a test bullet fired and then the scratches on the bullet will be compared.
Entry and Exit WoundsEntry holes are relatively neat and clean while exit wounds are far more ragged (and larger).
AutopsyAn autopsy is a medical examination performed on a body that has died under mysterious circumstances to determine time and cause of death. Forensic autopsies are performed by forensic pathologists while clinical autopsies are performed in hospitals by pathologists.
The procedure for an autopsy is as follows:
- the seal of the body bag is broken and the person is photographed
- evidence is collected off of external surfaces of the body
- any wounds are examined and the body is cleaned up
- the body is weighed and measured and then a general description of the body is recorded
- a deep y-shaped incision is made in the chest
- skin, muscle and soft tissue are peeled back using a scalpal
- the organs are examined
Causes of DeathNaturalA natural disease process such as leukemia or cancer.
AccidentDeath caused by a fall or car crash that is not homicide or suicide.
SuicideSelf-inflicted death.
HomicideUnnatural death caused by another person.
UndeterminedThe cause of death cannot be reasonably determined.
Time of DeathTime of Death Certainty PrincipleIf you know with certainty when the person was last known to be alive and you know with certainty when they were found dead then you know with 100% certainty that they died within that interval.
Ways of Estimating Time of DeathBody Temperature: A body's temperature falls around 1.5oC each hour after the person dies.
Rigor Mortis: Muscle fibres lock solid. This takes full effect after 6-8 hours and lasts for 20-30.
Lividity: Blood settles by gravity to the lowest parts of the body causing discolouration which becomes permanent after 3-5 days.
Cloudy Vitreous Humour: The corneas become cloudy.
Decay: The body turns green after two to three days.
Insect Evidence: Tells forensic scientists how long the body has been outside.
Identification- Remains and scars of illness, injury and operation.
- Unusual tatoos, birthmarks and piercings.
- Shape and structure of hair.
- Skeleton. (information about age and sex)
- Size of bones.
- Facial reconstruction.
- Dental remains and records.