These are the 911 calls from the night Trayvon Martin was murdered. The second call, which begins two minutes in, is from the shooter George Zimmerman, who explains his rationale for following and later killing Martin.

There's a real suspicious guy. ... This guy looks like he's up to no good, or he's on drugs or something. It's raining, and he's just walking around, looking about. ... Now he's coming towards me. He's got his hand in his waistband. ... Something's wrong with him. He's coming to check me out. He's got something in his hands. I don't know what he's doing. ... These assholes, they always get away.

You can hear Zimmerman following of Martin, and the dispatcher telling Zimmerman his pursuit is not necessary.

In other 911 tapes released, you can hear Martin screaming in pain (1:55) and the gunshot that killed him (2:40). The 28-year-old Zimmerman, who claims he was acting in self-defense, has yet to be arrested or charged with a crime.