claims he acted in self defense. ron motte has the latest developments from the courtroom. >> i felt his arm going down to my side and i grabbed it and i just grabbed my firearm and shot him. one time. >> reporter: more than 15 months after telling police his side of the story about the night he shot and killed unarmed 17-year-old trayvon martin, 29-year-old george zimmerman is now officially on trial for murder. >> i can tell you as a family we're very confident in the outcome of the case and very confident that the state will not be able to meet its burden. >> reporter: six panelists will be chosen to serve on the jury. >> the defense wants white jurors who love their guns and maybe a victim of the crime. the prosecution wants people that don't like the idea of vigila vigilantes. >> reporter: zimmerman pleaded not guilty to second-degree murder. his attorney says he acted in self defense after being attacked by martin. >> we are trayvon.