WATCH: ABC7's Autria Godfrey has reactions to the video, including footage of George Zimmerman's brother defending him.
MIAMI (AP) - Newly released police video of a handcuffed George Zimmerman may be important for what it doesn't show: No obvious cuts, scrapes, blood or bandages. No clearly broken nose. No plainly visible evidence of a life-and-death struggle with Trayvon Martin.
As the furor over race and self-defense raged on in Florida and around the U.S. on Thursday, Martin's family and supporters seized on the footage to dispute Zimmerman's claim that he shot and killed the unarmed black teenager after the young man attacked him.
While cautioning that the video is grainy and far from conclusive, some legal experts agreed it does raise questions about Zimmerman's story. The video was made about a half-hour after the shooting Feb. 26.
"It could be very significant," said Daniel Lurvey, a former Miami-Dade County homicide prosecutor. "If I were the prosecutor, it would certainly be Exhibit A that he did not suffer any major injury as a result of a confrontation with Trayvon Martin."
Zimmerman attorney Craig Sonner said on NBC's "Today" show that the footage appears to support his client's story in some respects.
"It's a very grainy video. ... However, if you watch, you'll see one of the officers, as he's walking in, looking at something on the back of his head," Sonner said. "Clearly the report shows he was cleaned up before he was taken in the squad car."
Zimmerman, a neighborhood watch volunteer in the town of Sanford, told police he shot the 17-year-old Martin after the young man punched him in the nose, knocked him down and repeatedly slammed his head against a sidewalk.
The Sanford Police Department video begins at 7:52 p.m., about 35 minutes after the shooting, as Zimmerman arrives at the station. It shows Zimmerman's head and face as he gets out of a police car.
There is no obvious wound on his head or blood on his clothing, and there are no indications of a broken nose - which Zimmerman's lawyer has insisted he suffered. He walks briskly, smoothly and unassisted.
"The explanation he is relying on is that there was a physical altercation," said Kendall Coffey, former U.S. attorney in Miami. "The intensity of the physical conflict is critical to his self-defense claim."
Benjamin Crump, an attorney for the Martin family, said the footage directly contradicts Zimmerman's story: "There are no marks on his face. There is no blood on his face. It's not like he's dazed or he has been injured."
Yet Ron Martinelli, founder of a California forensic consulting firm, said that Zimmerman was probably cleaned up when he was treated by paramedics at the scene and that in many cases there is no significant visual evidence of an injury.
"It really depends on how did the head strike the concrete? Did he get hit straight on in the face? Did he get hit with a fist or a backhand?" Martinelli said. "The video proves absolutely nothing."
Investigators have not released any paramedic or hospital records on the gunman.
The police report said that Zimmerman was found bleeding from the nose and the back of his head, and his back was wet and covered in grass, as if he had been lying on the ground. He was given first aid at the scene. According to his lawyer, he also went to the hospital the next day.
Zimmerman, whose mother is Hispanic and whose father is white, has not been arrested, despite demands from black leaders and others that he be charged with murder or manslaughter. But a special prosecutor appointed by the governor is investigating, along with state and federal authorities.
David O. Markus, a prominent Miami defense attorney, said that an actual fight does not need to take place for someone to claim self-defense under Florida's Stand Your Ground law, which gives wide leeway to use deadly force and eliminates a person's duty to retreat in the face of danger.
The video is yet another forensic challenge for investigators trying to unravel the case. Other key pieces of evidence include:
-The 911 call made by a woman who told a police dispatcher she could hear someone screaming for help, followed by a gunshot. The screaming voice can also be heard on the recording. Zimmerman told investigators it is his voice, but Martin's parents believe it is their son's. Martinelli said that investigators could do voice comparisons but that screaming is difficult to duplicate and match.
-A 911 call made by Zimmerman in which, to some people, he seemed to utter a racial slur while following Martin in his SUV. The raw recording is far from definitive. But recordings can be enhanced, and if Zimmerman did utter a slur, that could be evidence of racial bias and lead to federal hate-crime charges.
- The autopsy report, which has not been released. That could shed light on whether the angle of the bullet wound in Martin's body is consistent with Zimmerman's account of the confrontation.