Trayvon Martin Case

[Gary84Clark]

A medical examiner who reviewed video and photographs of George Zimmerman's injuries suffered during his fatal confrontation with Trayvon Martin called the neighborhood watch captain's wounds "insignificant" and "non-life threatening."

Dr. Valerie Rao testified that Zimmerman was struck as few as three times by Martin during the fight that night. She also asserted his head may have only been slammed on the concrete a single time. Zimmerman, who faces second-degree murder charges for the death of the unarmed teenager, said Martin repeatedly slammed his head on the concrete.

"Are the injuries on the back of the defendant's head consistent with one strike against a concrete surface?" asked prosecutor John Guy

"Yes," Rao said.

"And why do you say that?" asked Guy

"Because if you hit the head one time, it is consistent with having gotten those two injuries at that one time," she testified.

Rao's testimony could contradict Zimmerman's assertion that he was involved in a potentially life-threatening struggle with the Florida teenager.

Catch up on all the details from the George Zimmerman murder trial.

Zimmerman, 29, claims he shot Martrin, 17, in self defense on Feb. 26, 2012 as Martin repeatedly banged his head against the pavement and reached for Zimmerman's gun.