Evidence and Investigation Definitions

Accidental Characteristics – Marks, such as nicks, cuts, worn spots that are left on items because of
being used.
Example: Shoes may be the same kind but will leave different prints because of
how the person has used them.

Accuse – To blame or charge someone with a crime

Alibi – An excuse to tell others that a suspect wasn’t at the scene of a crime.

Bifurcation – A fork pattern found in a fingerprint.

Bite Marks – Just like fingerprints and DNA profiles, teeth marks can be used to identify
whether a suspect was at a crime scene as no two people have teeth that are exactly
the same size and shape.

Chain of Custody – Evidence from a crime scene is gathered, bagged, labeled and stored
at a police station. No one is allowed to see it unless they sign for it.
Keeping track of who looks at the evidence is called the chain of custody.

Chromatography – A technique that separates mixtures, especially colours.
Used to help identify ink and eventually pen brands.

Circumstantial Evidence – Evidence that by itself can’t prove a person is guilty, because many people
may have the same type of evidence, but can be used to support a case against a suspect.
Example: A shoe print is circumstantial because many people could have the same kind of shoe.
*Indirectly links a suspect to a crime

Conclusive Evidence – Evidence that directly connects a suspect to a crime.
Proves beyond a shadow of a doubt that a suspect was involved in a crime.
Example: DNA or fingerprint because no one has the identical DNA or fingerprints of another person.
Although identical twins do have the same DNA.

Classification – The arrangement of things into groups on the basis of a relationship between them.
We did this for leaves and for use of shoes.

Criminology – The study of why people commit crimes and how to prevent them.

DNA (Deoxyribonucleic acid) – cells in the body contain the chemical DNA.
Only identical twins have the same DNA code. It creates a pattern of bands that is called a profile.
Police match a suspect’s DNA with evidence collected to see if the suspect was at the crime scene.

Evidence – facts and clues that link a person to a crime.
An indication, a sign, the facts available for proving or supporting a notion.
Forensic evidence tends to support facts admissible in a court of law.

Fingerprints – Patterns of lines (ridges) on our fingers. No two people have the same fingerprints.
Police lift fingerprints from crime scenes and match to a suspect’s to see if the suspect was at the
crime scene.
There are 3 types of fingerprint patterns: WHORL, LOOP, ARCH
A fingerprint can be a combination of 2 or more of the main types of patterns. Fingerprints may be:

a) Patent Prints – visible prints
b) Plastic Prints – an impression of a fingerprint
c) Latent Prints – invisible to the eye – must be developed to become visible
Twins do not have identical fingerprints.

Forensic Science - The science that studies clues from physical evidence for use in the courts of law.

Fracture Matching – When something is broken or torn, the edges are fractured.
Investigators can use a broken item to do a fracture match because no two fractures are exactly alike,
the piece can be used as evidence.

Graphoanalysis - The study of handwriting, especially as a guide to character.

Graphology – The study of handwriting. Used to prove forgery.

Hypothesis – A guess made from known facts as the basis for an investigation.

Inference – an educated guess or judgment based on the facts or what you observe.

Investigation – A careful study of something in order to discover the facts about it.

Latent – concealed, not developed or not clearly visible – as in latent fingerprints.

Medulla – Pigment found in the structure of the hair.
Many people’s hair strands do not possess a medulla.
Medullas can be different hues and can be used as circumstantial evidence.

Observation – what you see or observe.

Perpetrator – a term used to describe someone who has committed a crime.

Pigment – a substance that imparts colour to other materials.

Police Sketches/Suspect Drawing – A police artist will draw a sketch of a suspect from

descriptions given by witnesses.

Polygraph – A lie detector test.

Prediction – a foretelling of what might be expected/what might happen.

Scenario – an imagined sequence of events.

Securing the Crime Scene – When investigators arrive at a crime scene, they tape it off.
This secures the scene by keeping people from entering it and either leaving new evidence or

taking evidence away.

Stakeout – To watch a suspect, watch their home or place of work.

Synthetic Fibres – A man-made material.