firearms

Some firearms considerations that need to be thought of in firearms investigations are

1)      If the gun is still loaded

2)      Distance from which the weapon was fired

3)      Type of gun used/caliber

4)      Powder patterns

5)      Primer residue on hands/clothes

6)      Check to see if the serial number if ground off

In a firearms investigation, a criminalist will be looking for casings, a gun (if one is there to find), stippling and/or tattooing on the person’s body, to determine range, this one might sound odd, but burnt skin; if the shooter was a novice with a gun and didn’t know how to properly hold the gun, trajectory height (tells the height of the person).

The significance of structural variations and irregularities is important to a case. It is like an individual tool or whatever used, it is like their fingerprints, unique to each tool because some may have more wear on them than others.  For instance, if a crime scene has a tool mark to pry open a door, and the person who owns the tool uses it every day for their job. It is going to have seriously more damage to it than it would if someone had bought one brand new for this “job”. These would be individual characteristics. If tit was brand new, it would be qualified as class characteristics.

Bullet examination, a criminalist will be looking for such things as striations on the bullet, rifling, number of lands and grooves, presence of grit and rust, weight to determine caliber.

Here is a shotgun shell with distinct markings of rust