By Barbara Liston
SANFORD, Florida (Reuters) - Volunteer watchman George Zimmerman suffered "insignificant" injuries in the fight in which he shot and killed unarmed black teenager Trayvon Martin, a medical examiner testified on Tuesday, as prosecutors attempted to undermine Zimmerman's claim he feared for his life.
Zimmerman has pleaded not guilty to a charge of second-degree murder, saying he shot Martin in self-defense during their confrontation inside a gated community in the central Florida town of Sanford on February 26, 2012.
Testifying for the prosecution at Zimmerman's trial, Medical Examiner Valerie Rao said she reviewed Zimmerman's medical records and 36 pictures of his injuries taken at the police station after the fight.
"They were not life-threatening. They were very insignificant," Rao told the Seminole County criminal court jury.
Zimmerman, 29, has said Martin, 17, punched him in the face and repeatedly slammed his head into a concrete walkway. Zimmerman, who is white and Hispanic, could face life in prison if convicted.
The racially charged case captivated much of the United States in 2012. Police initially declined to arrest Zimmerman, accepting his story of self-defense and sparking protests.
A special prosecutor later brought the murder charge. The prosecutor accused Zimmerman of profiling Martin and chasing him vigilante-style rather than waiting for police to arrive.
In court on Tuesday, medical examiner Rao said Zimmerman's injuries did not involve great force and were consistent with one blow to the face and one impact with the concrete. He had a broken nose and two small cuts on the back of his head.
But later under questioning by one of Zimmerman's lawyers, Rao said Zimmerman could have been hit more than once.
David Weinstein, a former prosecutor and Miami-area defense lawyer, cautioned against reading too much into Rao's testimony in a case that centers on Florida's self-defense laws and the justified use of deadly force.
"There is no requirement that you prove that you were injured to any particular degree. Only that you believed that deadly force was necessary to defend yourself from 'imminent death or great bodily harm,'" said Weinstein, who is not involved in the case.
Martin was a student at a Miami-area high school and a guest of one of the housing development's homeowners. He was walking back to the home in the rain from a convenience store when Zimmerman spotted him and called police, saying Martin looked suspicious. There was a confrontation between the two in which Zimmerman shot Martin through the heart with a handgun he was licensed to carry.
Earlier on Tuesday, the judge ordered jurors to ignore part of the testimony they heard the day before, when the police officer who initially led the investigation in the case said he believed Zimmerman's account of the killing was truthful.
Sanford Police Officer Chris Serino said he falsely told Zimmerman the entire encounter had been videotaped in a bluff to see if he would stick to his story of shooting in self-defense after Martin attacked him. Zimmerman seemed "very elated" at the prospect of a video record, Serino said, leading him to conclude the defendant was either telling the truth or was a pathological liar.
"Do you think he was telling the truth?" asked one of Zimmerman's lawyers, Mark O'Mara.
"Yes," Serino replied.
Judge Debra Nelson said witnesses were not supposed to comment on the credibility of other witnesses or defendants because it was the jury's job to decide who to believe.
She ordered the six-women jury to ignore that exchange, highlighting one of the pitfalls of a trial: improper evidence sometimes falls on the jury's ears.
Like many of the witnesses so far, Serino seemed to bolster both prosecutors' and defense attorneys' interpretation of events, depending on who was questioning him.
He said he questioned Zimmerman's claim that he got out of his vehicle to look for a street address to give to the police dispatcher, noting Zimmerman had parked on a road near the neighborhood's entrance, in front of a home with a clearly posted street number.
"It did raise flags and concerns," Serino said.
In order to win a second-degree murder conviction, prosecutors would have to convince the jury that Zimmerman acted with "ill will" or "hatred" and "an indifference to human life."
Prosecutor Bernie de la Rionda asked Serino about vulgar language Zimmerman used to describe Martin during his call to police just before the fatal scuffle.
"That is ill will and spite," Serino said.
Asked whether Zimmerman had profiled Martin as a criminal when he repeatedly referred to him as "the suspect," Serino replied, "It could be construed as such."
Serino also said he thought Zimmerman had exaggerated his description of the blows that he claims Martin inflicted on him.
Despite Zimmerman's claim that Martin had put his hands over his mouth and nose to smother him, prosecutors have said there was no blood and none of Zimmerman's DNA on Martin's hands or clothing.
(Additional reporting by Tom Brown; Writing by Jane Sutton; Editing by Grant McCool)