Trayvon Martin punched George Zimmerman, climbed on top of him, and banged his head into the sidewalk several times before a bloodied Zimmerman shot and killed him. Or at least, that's what Zimmerman told police in the wake of the shooting, and authorities tell the Orlando Sentinel that witnesses have corroborated a good deal of the account. Zimmerman says he'd given up on tailing Martin after losing sight of him, and was returning to his SUV, but the teen followed him and confronted him.
According to Zimmerman, Martin then asked if he had a problem. When Zimmerman said no, Martin replied something along the lines of, “Well, you do now,” and hit him in the nose. Zimmerman fell to the ground and screamed for help, he says, as Martin slammed his head into the concrete. Witnesses have disagreed on whether the screams they heard came from Martin or Zimmerman, but at least one has publicly said he saw the pummeling. Police also confirm that when they arrived on the scene, Zimmerman had a bloody nose, a swollen lip, and lacerations on his head. But other witnesses have painted a less sympathetic picture of the event. (Read more Trayvon Martin stories.)