Report: Zimmerman described as "Jekyll and Hyde"

(CBS News) - An anonymous former co-worker of George Zimmerman, the man who shot and killed unarmed teen Trayvon Martin five weeks ago, told a newspaper that Zimmerman "loved being in charge ... loved the power" and could become violent.

The New York Daily News reported Friday that Zimmerman was fired in 2005 from his job as a party security guard for being too aggressive, quoting a former co-worker as saying that "usually he was just a cool guy. ... But it was like Jekyll and Hyde. When the dude snapped, he snapped."

As the negative reports start to mount, Zimmerman's family has come to his defense.

Robert Zimmerman, Jr. stuck up for his brother to CNN's Piers Morgan Thursday night.

"He prevented his firearm from being taken from him and used against him, and that's called saving your life," he said.

Zimmerman said his brother shot Martin purely in self-defense, after the teenager attacked him last month. "You return force with force and when someone assaults you," he said. "George was out of breath. He was barely conscious. The last thing that he remembers doing is moving his head from the concrete to the grass, so that if he was banged one more time, he wouldn't be wearing diapers for the rest of his life and being spoon-fed by his brother."

But critics, including Martin's parents, say recently released police surveillance video is proof Zimmerman's a liar. Seen on the tape, Zimmerman had no obvious face or head injuries.

Zimmerman Jr., Thursday night said his brother still had a broken nose. "His nose, I don't know about his head. I mean his nose is still healing. It's not healed.

Martin was buried in Miami. Richard Kurtz, the funeral director who prepared his body said, "We could see not physical signs like there had been a scuffle for fight."

Kurtz said Martin's chest had a gunshot wound, but his body had no other injuries. No marks on his hands from all the punches Zimmerman claimed had battered him.

A special prosecutor's now reviewing all the evidence, to decide whether Zimmerman can legitimately claim he killed to save his own life.

Mark Strassmann

Mark Strassmann is CBS News' senior national correspondent based in Atlanta. He covers a wide range of stories, including space exploration. Strassmann is also the senior national correspondent for "Face the Nation."