n October 1999, at approximately 3:30 am, a woman called police, reporting that she had just been sexually assaulted. She had been awakened in the middle of the night by a subject attacking her. He put a pillowcase over her head and raped her repeatedly over a period of about two hours. He then tied her up and left the residence.

As a crime scene technician, I responded to the scene with officers and detectives. I was able to sit in on the initial interview with the victim. I learned that during the time the suspect was in the house, he had touched several items in the home, such as drinking glasses, soda cans, and various items in the victim’s bedroom. The victim advised that the perpetrator had used paper towels to wipe down these items, and to wipe his hands after using some lubricant during the assault.

Processing all of the items at the scene yielded negative results. In addition to several other items, I collected the paper towels that the victim advised the suspect had used, as well as the entire roll.

Before processing the collected paper towels, I experimented with clean paper towels of the same brand. Lab personnel placed prints on several of these control pieces. Some sheets were dipped into a tray of ninhydrin, while others had ninhydrin applied by a steady stream from a wash bottle. Steam was applied to expedite the development of results. After inspecting the results of both types of application, it was concluded that the wash bottle application yielded better results.

Ninhydrin was then applied to the two paper towels that the suspect was known to have handled. The towels were each placed in a plastic ziplock bag and left in a dark area. When checked seven hours later, a distinct handprint had developed on one sheet, with ridge detail located in the interdigital and thenar area of the palm.

Latent print examiner Kelly Speckels identified the palm print to the suspect in the case. Ultimately, the suspect entered into a plea agreement and was sentenced to 24 years in prison.