Despite FSRC findings to the contrary, some law enforcement sources still regard spent shell casings as immutable pieces of forensic evidence and seem prepared to rely on them to judge the truthfulness of officers’ accounts of controversial shootings.
Consider a New York Times report on Dec. 8 about the investigation into the high-profile New York City case in which a prospective bridegroom was killed in a 50-shot fusillade from police officers after he exhibited threatening behavior outside a strip joint.
Reporters Al Baker and William Rashbaum stated that “ballistics evidence will paint a picture of the shooting that prosecutors can use to help gauge the accounts of potential witnesses, including the five officers who fired into [the suspect’s] car, killing him…and injuring two of his friends.”
They then quoted an anonymous “law enforcement official who has investigated several police shootings” as saying this about the “valuable information” spent shell casings can provide at a shooting scene:
If an officer is moving while shooting, “you’re going to have almost like a trail of breadcrumbs, or clusters if he moves, stops, fires and moves again. If he stands and fires, there will be a big pool of brass.” In other words, you can reliably mark a shooter’s location by where his brass lands.
Don’t be too sure. FSRC experiments have demonstrated conclusively that casings can end up virtually anywhere, depending on how a handgun is being held when fired.
“If you don’t know how a gun is being held and manipulated at the time the shell is ejected, the presence of a casing in any given spot will only tell you that a gun was fired at the scene,” says Dr. Bill Lewinski, FSRC’s executive director who led the Center’s ground-breaking studies on ejection patterns. “Depending on how you hold the gun, you can put brass into a pool, for example, from any point on a 360-degree circle around the pool.”
FSRC began investigating this subject several years ago after a motor officer was brought to trial in Arizona on murder charges by a prosecutor who believed that a shell ejected from the officer’s pistol proved he was lying when he said he was in the path of an oncoming car at the time he decided to shoot the driver.
For details on the Center’s findings, see: a previous Force Science News Transmission found at:
https://www.forcescience.org/2004/12/new-findings-on-shell-ejection-patterns-help-clear-officer-on-trial-for-murder-2/
and Transmission #20 [5/31/05] found at:
https://www.forcescience.org/2005/05/new-shell-ejection-study-suggests-gun-handling-determines-where-empties-fall/