. >> he has not did this, no. >> reporter: lisa epps stood in her front doorway, expressing her unwavering support for her son, mark, saying he hasn't been in touch with his estranged girlfriend, natasha gibson, for a while. >> he has not seen that girl for eight, nine months. >> reporter: yeadon police don't believe it. the chief says gibson's family told officers a different story. >> there's threats of violence from him just recently in the last month. so she was fearful for her safety because of this individual. >> reporter: around 3:00 this morning, gibson's body was found outside a family friend's house, her throat slashed. the killer got away on foot. a long trail of blood from yeadon to the outskirts of southwest philly led investigators to what's believed to be the bloody steak knife used in the killing. >> the investigation of the crime scene showed us that the suspect apparently was also injured, and he was bleeding. >> reporter: later police told nbc10 about the search for mark epps. a man with a criminal history which includes past charges of assault, reckless endangerment, an