TIME ALONE DID NOT APPEAR TO SERIOUSLY DEGRADE LATENT FINGERPRINT QUALITY OVER THE THREE-WEEK PERIOD OF EXPERIMENTAL TRIALS. THE GREATEST EFFECT OF DETONATION SEEMED TO STEM FROM HOT GASEOUS BLOWBACK ON THE EXTERNAL SURFACE OF THE CARTRIDGE CASINGS. NICKEL-PLATED CASINGS, BECAUSE OF THEIR GREATER CHEMICAL RESISTANCE AND MORE POLISHED SURFACE, WERE FOUND LESS SATISFACTORY AS A SUBSTRATE FOR LATENT IMPRESSIONS THAN BRASS CASINGS. AN INTERESTING TECHNIQUE FOR DEVELOPMENT AND PERMANENT PRESERVATION OF LATENT FINGERPRINT IMPRESSIONS ON CARTRIDGE CASINGS WAS ALSO DESCRIBED. THIS TECHNIQUE INVOLVED ETCHING THE LATENT FINGERPRINT IMPRESSIONS DIRECTLY ON THE CARTRIDGE CASINGS BY EXPOSING THEM TO NITRIC ACID VAPOR, THUS ENABLING THE FINGERPRINT TO BE PRESERVED RIGHT ON THE PIECE OF EVIDENCE. (AUTHOR ABSTRACT MODIFIED)