The defendant in this case was charged with unlawful possession of a firearm by a felon and aggravated assault. The weapon in question was an unloaded pneumatic rifle, and one of the key questions litigated at trial was the officer’s use of a chromograph without any training other than his amateur use to allow an opinion that the rifle in question was a firearm based on the tracked velocity of fired ammunition.
The appellate court held that this testimony was admitted without proper foundation finding multiple reasons why there was no reason to believe that the expert would know his chronograph was working properly as well as the fact that this officer was testifying solely based on his experience and not any recognized scientific methodology.
The Appellate Court therefore reversed and remanded for a new trial.
The case is People v. Jeremy Thompson.