been fresh when he stepped on it. >> this proved that the only evidence at the crime scene was carlos robinson's was a victim of her own trusting nature. carlos was her neighbor. they already met. so when he knocked on her door, she let him in. >> how are you doing? >> carlos wasn't wearing any shoes since he lived next door. once inside, prosecutors believe he made a sexual advance which christina turned down. so carlos hit christina with tremendous force, knocking out three of her teeth. he then dragged her to the bathroom where he sexually assaulted her and killed her with a knife. he filled the tub with water in an attempt to wash away evidence, but he grabbed the sink with his bloody hand as he got up leaving behind a perfect palm print. he needed to get rid of the murder weapon, so he went to the kitchen, tracking his bloody footprints. he grabbed a bag of hamburger buns, dumped them on the floor, then put the knife inside the bag so it wouldn't leave a blood trail when he left. on his way out, he stepped on one of the buns leaving the one piece of forensic evidence he couldn't refute. rob