Impression Evidence

Impression Evidence

Any physical evidence that leaves behind a distinct pattern through direct contact between an object and a surface (such as bite marks, shoe prints, tire marks, tool marks, and ballistics).

Circumstantial Evidence (Impressions)

Type of evidence that it can be collected, observed, and scientifically analyzed in a laboratory.

Pattern Evidence

A classification of physical evidence that makes a pattern.

Forensic Odontology

The specialized branch of forensics where analysts study dentition to identify human remains and examine bite mark patterns on victims, suspects, or scene objects.

Enamel

The strongest substance produced by the human body.

Bite Mark Stage One

The immediate indentation formed in skin from a bite, typically lasting between 1 and 10 minutes.

Bite Mark Stage Two

Stage of bite mark where inflammatory swelling develops, frequently obscuring distinct individual tooth marks for several hours.

Bite Mark Stage Three

The final stage of a bite where bruising forms from the breaking of blood vessels.

Bite Mark Scale (Level 1)

A severity rating describing a faint arch with no individual tooth marks that may have been caused by an object other than human teeth.

Bite Mark Scale (Level 2)

A severity rating describing a mark showing some bruising without broken skin, some tooth marks are visible.

Bite Mark Scale (Level 3)

A severity rating describing an obvious bite mark characterized by bruising and/or SLIGHT lacerations at the tooth impressions.

Bite Mark Scale (Level 4)

A severity rating describing an obvious bite mark characterized by HEAVY bruising and/or deep lacerations that shows most tooth impressions.

Bite Mark Scale (Level 5)

A severity rating describing a bite mark involving PARTIAL loss of tissue.

Bite Mark Scale (Level 6)

A severity rating describing a bite mark involving COMPLETE loss of tissue, accompanied by scalloping around the wound edges.

Overlay Method

The comparison technique where a transparent sheet is placed over a suspect's teeth mold to trace tooth positions to compare to crime scene bite marks.

Compression Mark (Tool)

An impression created when a tool is pushed into a surface with force.

Striation Mark (Tool)

A scratch mark composed of microscopic ridges and valleys produced when the working edge of a tool scrapes across a surface, revealing unique individual imperfections.

Common Approach Path

A designated pathway established by crime scene investigators away from criminal points of entry and exit to prevent the destruction of footwear impressions.

Accidental Characteristics (Footwear)

Individualizing physical marks on a shoe outsole, including cuts, nicks, wear patterns, and rips.

Ballistics

The scientific study of projectiles, firearms, and the mechanical and wounding effects of firing on bullets, cartridges, and weapons.

Internal Ballistics

The branch of ballistics that studies processes that occur inside the firearm from the time the trigger is pulled until the bullet exits the muzzle.

External Ballistics

The branch of ballistics that examines the flight path of a projectile from the moment it leaves the barrel until it impacts the target.

Terminal Ballistics

The branch of ballistics (also called wound ballistics) investigating projectile behavior upon impact with a target.

Lands and Grooves

The raised metal ridges (lands) and spiral cut channels (grooves) manufactured inside a rifled bore to impart stabilizing spin to the bullet.

Caliber

The measure of the diameter of a bullet.

Gunshot Residue (GSR)

Microscopic, sticky unburned or partially burned particles that exit the gun when it is fired

Contact Gunshot Wound

A gunshot injury produced when the weapon's muzzle is held against the skin, characterized by internal burning.

Close Range Gunshot Wound

A gunshot injury sustained from 2 to 12 inches away, marked by sooting (fouling) around the wound.

Intermediate Range Gunshot Wound

A gunshot injury from 1 to 3 feet away, identified by stippling caused by unburned gunpowder grains embedding into the skin.

Distant Gunshot Wound

A gunshot injury from more than 3 feet away, has no stippling, fouling, or burn marks.