to look at the calendar because i don't know where i was that day but i guarantee you i wasn't in oldsmarwe go from there to discussing where i was, who i had been with, where i lived. >> so are you getting a serious grilling? >> right. he ends up telling me that we found your name in blood on the wall. >> roc? >> so, obviously, i'm a suspect. i acknowledge that. i mean i'm looking at murder. i'm getting somebody's talking to me about a murder. >> roc waved his right to a lawyer and agreed to give fingerprints and swabbing. it looked as though police found yet another cooperative boyfriends from the victim. >> i said, if you are looking for fingerprints, they're all over that home. i lived there a year. you are going to find them. >> did you lose your patience? >> no. i did lose my patience when they take the end of my fingernail off taking my fingernail. now i'm done. >> roc's cooperation had an edge to it. was he really trying to cover his tracks? detectives were determined to find out. >> and they put that bloody clue under the microscope. were those three little letters really what th