>> bubbly surface. >> knobing grippy surface. i remember thinking, wow, i wonder if that's what wrote these letters. >> cox bought similar gloves at a hardware store. after several more days of testing was satisfied that her hunch was correct. anna cox came one two important findings. the message in blood had likely been written with a gloved hand and it had been scrawled at least 20 minutes after the onset of the attack on karen. she reported her results to the detectives, that learned a fact about the victim. >> karen was exclusively left handed and her left hand did not have blood smear on it. >> not only that, when the autopsy report came in it suggested karen couldn't have written anything with either hand. from what the medical examiner was seeing, was this a victim who was going to dip in her own blood and write roc on the wall?