Free Lead Particles Associated with Keys

The defendant was accused of the shooting death of his wife. Police administered gunshot residue samplers to the defendant's hands and objects that he likely came into contact during the interval from the shooting to his arrest. The examination of the samplers by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) showed no particles of potential gunshot residue, except the sampler of a set of keys from the defendant picked up lead-containing particles. The criminalist called these particles “consistent with gunshot residue.” There were no control examinations (i.e., testing other sets of keys) made. As will be seen below, it is unlikely that the source of the lead particles found by the criminalist originated from a firearm.