1. Criminal Investigations

2. Curriculum Connections:
explain processes of police investigation
explain pre-trial procedures, including processing evidence
NOTE: This information is not on your Unit Test on Jan corresponds with pages

3. The Crime Scene
Police have the right to cordon off the crime scene to make sure no evidence is lost or tampered with.
if the incident involves a death, the coroner has jurisdiction over the area.
Police have the right to refuse to enter a crime scene

4. The Crime Scene
Forensic Evidence - Area is photographed and searched for items such as hair or fibre samples, blood, forced entry, physical struggle, fingerprints, footprints, or weapons
Questioning of witnesses will also take place by police officers

5. Processing Physical Evidence: Fingerprints
Forensic scientists analyze the information collected
Fingerprints are compared with those on file at the RCMP central repository in Ottawa.
The patterns of ridges on our fingerpads are unique

6. Nothing can really change the ridge structure: when new skin grows in, the same pattern will come back.
Dactyloscopy
the practice of using fingerprints to identify someone.

7. It is possible for mistakes to be made in fingerprint identification
usually only a portion of a print is available and can be distorted and hard to read, especially in a messy crime scene situation
It’s important for specialists are able to properly dust and lift fingerprints at a crime scene to be able to classify and match them to those in the database.

8. Classifying Fingerprints
All fingerprints can be identified as one of three types: Arches, Loops, Whorls
Arches: forming ridges that run from one side of the print to the other and curve up the middle

9. Loops: showing stronger curves than arches with ends that start on one side of the finger, loop around and end up in the same place

10. Whorls: forming complete ovals, often in a spiral pattern around a central point.

11. Crime Scene Procedures
There are strict procedures on the seizure, handling, and storage of evidence:
no evidence is left unattended;
the case officer must secure evidence in the police property locker;
transferring evidence is the responsibility of the case officer;
no evidence can be removed from property locker without appropriate authority and signature. This is to maintain the chain of custody of the evidence.

12. Trace Elements Small particles such as dirt, dust, and residue
Provides a link between a crime and the suspect(s)

13. The transfer of hair and fibres
Typically analyzed in homicides, kidnapping and aggravated assault
Hair and fibres are trace elements that are very widespread -- they can be found either on the victim or the accused.
Hairs may not reveal the identity of a specific person (like fingerprints can), but they can reveal racial background, area of the body the hair came from, and the person’s blood type.

14. Animal fur (contains more scales than human hair)
Human hair samples with the root can provide the most information – DNA is usually present.

15. Fibers from the crime scene can be traced to criminals
(Example: Carpet fibres from the crime scene found on the shoe of a suspect)
Fibers from the crime scene can be traced to criminals

16. Blood
Blood samples become important in impaired driving cases or crimes committed when under the influence
Percentage of alcohol or substance levels can be important in cases where mens rea is an issue.

17. Blood Spatter Analysis
study of the size and shapes of the drops on the floor can determine from the height at which they fell
The shape of drop can indicate movement and direction
Blood spatter on the wall can determine force and direction of the blow.

18. DNA
Lab analysis of blood stains, semen, saliva, skin and hair follicles can lead to the identification of an individual through his or her distinctive genetic code
All human beings have a genetic code within their chromosomes which are composed of DNA and which is distinct from any other person