George Zimmerman, charged in Florida with shooting an unarmed black teenager, sued NBC Thursday, charging an edited 911 tape defamed him. In a complaint filed in Seminole County in Florida, Zimmerman said the network edited the tape to make him appear racist, CNN reported. Two former reporters were also named as defendants. \"NBC saw the death of Trayvon Martin not as a tragedy but as an opportunity to increase ratings, and so set about to create the myth that George Zimmerman was a racist and predatory villain,\" the complaint says. Zimmerman, a neighborhood watch volunteer in Sanford, Fla., says he shot Martin, 17, in self-defense after the teenager assaulted him. He called 911 after spotting Martin, who was walking to a relative\'s house, and ignored a suggestion from a dispatcher that he should back off. In the lawsuit, he says NBC engaged in \"deceptive and exploitative manipulations.\"