because she had to work the nextnext day. she had to go into work early. after saying good-bye, he said he spent an hour with friends an hour to the north. is he saying anything, he can t do it? i know boyfriends are figured suspicions, i want to talk to a lawyer? no, he s being more than cooperative. while tim says he was off with his friend, there appeared to have been a frenzied struggle at karen s house. forensic specialist ana cox described the aftermath. she put up a heck of a struggle. what are you looking at? she had defensive wounds, the way her body was contorted. i was thinking, she fought for her life. do you think oh my goodness or have you seen everything at this point? i can t believe what people do to each other. it s terrible. reporter: around the back, cox, the crime scene tech, found the security bolt on a sliding
wonder if that s what wrote these letters. cox bought similar gloves. ana cox had come up with two important findings. the message in blood had likely been written with a gloved hand and had been scrawled at least 20 minutes after the on set attack on karen. she reported to her results to detectives who by then had learned another pertinent fact about their victim. karen was exclusively left-handed and karen s left hand did not have blood smeared on it. not only that, when the autopsy report came in it suggested karen could not have written anything on either hand. was this a victim going to be able to dip in her own blood and write roc on the wall in. no, absolutely not. over 90% of her spinal cord had been damaged by knife wounds.
gruesome canvas for the letters roc then written over it. when the letters were wren on top it, it just skimmed right over it and didn t disrupt it at all. since the specks of blood weren t smeared that must have meant roc must be have been written after they dried. but how long after? in her lab she used animal blood to test how long it took for spatter to dry on a similar surface. so once i came back and was able to apply spatter to some secks of some cardboard, then i was able to get some blood and start writing the word roc. i must have wren this word a million times over different areas of spatter. in the lab it took at least 20 minutes of drying time before the forensic specialist could write without smearing the spatter. she concluded there must have been about that much time between the attack on karen and the word roc being written on
investigation. the letters roc smeared on a wall matched karen s former boyfriend roc. and soon a forensic break through would force detectives to reconsider the bloody clue. not only what it meant but who wrote it. here again is dennis murphy. reporter: the handwriting was on the wall and forensic specialist ana cox was intent on breaking down the key piece of evidence implicating karen s first boyfriend roc. you would spend hours looking at these letters. you actually cut the sheetrock out of the place and took it into your lab? yes. i have to look at those letters, at everything about them. using a high powered microscope ana did an analysis of the specks of blood as karen was stabbed 16 times. that flow spatter served as a