composite. investigators suspected that the killer might have left fingerprints on the duct tape he used to bind the murder victims. it s difficult to handle tape without touching the sticky side. so analysts treated the tape with gentian violet, a chemical dye. when the tape is immersed in the gentian violet, the dead skin cells that are pulled from the fingers of palms of the hand will then react with the gentian violet and you get a nice, dark image of the latent prints. just as they suspected, the killer left behind two clear prints. when he was binding the ladies, he was touching the sticky side of the tape. the prints did not match the cable repairman, and he was eliminated as a suspect.
the killer might have left fingerprints on the duct tape he used to bind the murder victims. it s difficult to handle tape without touching the sticky side. so analysts treated the tape with gentian violet, a chemical dye. when the tape is immersed in the gentian violet, the dead skin cells that are pulled from the fingers of palms of the hand will then react with the gentian violet and you get a nice, dark image of the latent prints. just as they suspected, the killer left behind two clear prints. when he was binding the ladies, he was touching the sticky side of the tape. the prints did not match the cable repairman, and he was eliminated as a suspect. next, investigators tried to identify roxanne s 11:00 a.m. appointment.