involved. >> the sweatshirt was given to forensic analyst mary wong. since the killer used a .38-caliber handgun, there was the potential of gunshot residue on the sleeves. >> when a weapon is discharged, a cloud of gas is formed and then these particles are then deposited on any surface in the vicinity of the discharge. >> wong processed the sleeves and cuffs with a stub sampler, an aluminum disk with a carbon tape adhesive surface. the sample was bombarded with electrons, and the x-rays revealed three chemical elements -- lead, antimony and barium. >> if those three elements are present, then that leads me to believe that that particle is actually a primal gunshot residue particle. >> this meant kevin rice's killer was wearing this sweatshirt.