A girl who overheard part of an incident involving Florida teenager Trayvon Martin can help prove he was killed "in cold blood" by George Zimmerman, a neighborhood watch volunteer, an attorney for Martin's family said Tuesday. The girl, who was dating the 17-year-old, "completely blows Zimmerman's absurd self-defense claim out of the water," lawyer Benjamin Crump told reporters. The girl -- who he said does not wish to be identified -- "connects the dots" about what happened that day when she lays out what she overheard while on the phone with him, he said. 911 calls paint picture of chaosSanford police say they asked all witnesses to come forwardGovernor says he will work to see "justice prevails"George Zimmerman was bleeding from the nose and back of his head, a police report saysThe 17-year-old was not armed when he was killed last month in Florida
_ was fatally shot on February 26 while walking to the house of his father's fiancee in Sanford after a trip to a nearby convenience store. The girl said that, during the phone call, she heard someone ask Martin what he was doing and heard _ ask why the person was following him, Crump said. Morgenstern said _'s cell phone was collected from the crime scene and investigators were working to acquire records associated with the phone's use. Martin's family insists it was _ who was heard yelling for help. In his statement last week, _'s father said his son never followed or confronted Trayvon. He's coming to check me out," _ tells a police dispatcher.