Page 2 - Jon Osterman News Today : Breaking News, Live Updates & Top Stories | Vimarsana

Testimony couldn't help zimmerman. >> i only heard the story twice, and whether it was grabbed the gun, grabbed for the gun, i just -- perhaps it was just the intent. but i believed he said he grabbed the gun. >> reporter: months before the trial, osterman, a federal air marshal, described to me in detail how he helped zimmerman weigh the pros and cons before he settled on buying a thin, lightweight .9 millimeters. it was easy to conceal, easy to carry. and acting on osterman's advice, zimmerman carried it everywhere. >> always. he carried it always. the one thing i did tell him, for the reaso...

Arm and i grabbed my gun and i aimed it at him and fired one shot. >> reporter: dna testing seems to agree. there was no trace of trayvon martin's dna on the gun's grip. prosecutors list osterman's book with zimmerman's conflicting account as potential evidence, possibly to challenge zimmerman's credibility. as for his connection to the gun zimmerman was carrying, osterman says it's hard to answer the question does he feel regret. >> so, i would wish it would have never happened. however, the reason why george had it, it was not for malice. he didn't have it to go out and commit a crime of hun...

The jury will have to decide that, and i think once they think about those two things, it will be rather clear what's relevant and what's not. >> benjamin crump, always good to talk to you and thank you very much for taking the time. one of george zimmerman's best friends could complicate his defense. mark osterman came to zimmerman's aid the night he shot and killed trayvon martin, and the account that he says zimmerman told him about what happened that night doesn't add up to some of zimmerman's later statements. david mattingly is "outfront" with the story. >> reporter: when george zimmer...

Afraid? >> no. >> that something may have happened? >> no. the thing was, was he had felt that once he gets married -- once you get married he said that he possibly changed his perspective in life and that he was responsible not just for himself anymore but for his wife. >> reporter: osterman, a federal law enforcement officer, helped zimmerman weigh the pros and cons before he settled on a thin lightweight 9 millimeter. it was easy to conceal, easy to carry, and acting on osterman's advice, zimmerman carried it everywhere. >> always. he carried it always. i -- the one thing i did tell him for...