Criminal Investigation Basics
This field uses science to examine evidence and help investigate crimes.
Forensic Science
Before searching for clues, officers check the victim and get this help if needed.
Medical Help
Name the three main fingerprint pattern categories.
Arch, Loop and Whorl
This word describes deliberately setting a fire to damage property.
Arson
An investigator finds a fingerprint left in wet paint that can easily be seen. This is this type of print.
A Visible Print
Hair strands, tiny fibers, and skin cells are examples of this small—but important—type of evidence.
Trace Evidence
Officers use crime scene tape to keep people out and prevent this from happening to evidence.
Contamination or Disturbing the Scene
In this pattern, ridges enter from one side, curve around, and exit on the same side.
Loop
Gasoline used to help a fire spread is an example of this.
An Accelerant
An officer photographs evidence before collecting it. Explain why this order matters.
The photographs preserves the evidence original location and condition before its moved.
Statements from an eyewitness or an expert who analyzed evidence belong to this evidence category.
Testimonial Evidence
A bank robbery happens at the bank, but investigators find the stolen money in an abandoned house. The house is this type of crime scene.
Secondary Crime Scene
A finger pressed into soft gum leaves a three-dimensional impression. This is this type of print.
Plastic Print
Investigators use this term for the location where a fire began.
Point of Origin
A witness saw someone for only a few seconds in a dark alley. Name two factors that could affect the witness’s identification.
Poor lighting and short viewing time
A suspect owns the same type of gun used in a crime. This provides an indirect connection and is this type of evidence.
Circumstantial Evidence
Investigators photograph a shoeprint beside a ruler so they can determine this about the print.
The Size or Scale of the Print
Investigators use powder to reveal a fingerprint that was invisible. The invisible print is called this.
Latent Print
Someone deliberately burns their business to collect money from an insurance company. This is the motive.
Insurance Fraud or Financial Gain
AFIS suggests possible fingerprint matches. These people make the final comparison to check the identification.
Fingerprint Examiners or AFIS Technicians
A person leaves fibers at a scene and carries away dirt on their shoes. This exchange illustrates this scientist’s principle.
Locard's Principal
This record tracks who collected, received, and handled each piece of evidence.
Chain of Custody
This chemical reacts with amino acids in fingerprints on paper, making the prints appear purple
Ninhydrin
An arson dog alerts investigators to an area of debris. They collect samples and send them here to test for ignitable liquid residues.
A Forensic Laboratory or Crime Lab
A fingerprint on a window belongs to a suspect. Explain why that finding alone does not prove the suspect committed the crime.
It suggests the person touched the window at some time, but does not establish when, why, or whether they committed the crime.