tunnel vision. he was able to smack the hand away from the firearm, and that's when he drew the firearm and fired. >> reporter: osterman wrote about it in a book, quoting zimmerman -- "somehow, i broke his grip on the gun where the guy grabbed it between the rear site and the hammer. i got the gun in my hand, raised it toward the guy's chest and pulled the trigger." and this is where the problem lies for george zimmerman, because comments quoted by his friend, osterman, do not match what zimmerman told police. listen to what he says as he walks investigators through the crime scene. >> and he reached for it, but he reached -- like, i felt his arm going down to my side, and i grabbed it and i just grabbed my firearm and i shot him one time. >> reporter: in multiple recorded interviews, zimmerman never tells police that trayvon martin ever touched his gun. >> and i saw him take one hand off my mouth and slide it down my chest, and i just pinched his