The skepticism is at odds with a public perception that the police department didn't fully investigate the neighborhood watch leader in the aftermath of the shooting. Zimmerman was arrested more than a month after the shooting, and only after the local police department said they were not going to charge him.
The evidence was made public by Zimmerman's attorney almost a week before Zimmerman's second bond hearing on a second-degree murder charge, and on the heels of unflattering telephone calls capturing Zimmerman and his wife talking in code about using money collected for a defense fund to pay credit cards.
Making it public now may help Zimmerman "because this is a case being played out in the press," said criminal defense attorney David Hill, who is not involved in the case.
"If there is a strategic basis, I don't think it hurts," Hill said. "I don't think it hurts his client at all."
The tapes give Zimmerman's most detailed account yet of what led to the Feb. 26 shooting. In one video, he goes to the scene of the shooting and re-enacts for police what happened, answering probing questions from authorities.
In an interrogation at the police station, a detective points out inconsistencies in his story, particularly Zimmerman's claim that Martin confronted him, punched him and slammed his head onto the ground when the teenager had no prior history of violence.
Detective Chris Sereno asks Zimmerman whether he was profiling Martin because he was black, a claim Martin's parents have made.
"You know you are going to come under a lot of scrutiny for this," Sereno said. "Had this person been white, would you have felt the same way?"
"Yes," said Zimmerman, who father is white and his mother Hispanic.
Zimmerman claims he shot the unarmed 17-year-old Martin teen in self-defense, under Florida's "stand your ground" law.
Martin's parents have said Zimmerman was the aggressor. They said Martin was walking back from a convenience store through the gated community in Sanford when Zimmerman spotted Martin and started following him.
In the video (http://apne.ws/KWquJX ), Zimmerman said he grabbed his gun from a holster on his waist before Martin could get it, and shot Martin once in the chest as they fought on the ground outside townhomes in a gated community. After firing, Zimmerman said he thought he missed.
"He sat up and said, 'You got me. You got me, or something like that,'" Zimmerman said.
Zimmerman said Martin had been on top of him, slamming his head against the ground and smothering his mouth and nose with his hand and arm. The tape shows two butterfly bandages on the back of Zimmerman's head and another on his nose. There are red marks on the front of his head.
"It felt like my head was going to explode," he said.
Hill, the defense attorney, said the video didn't show Zimmerman to be the zealous "cop-wannabe" that Martin's parents have portrayed.
"I didn't see him being too slick on the details," Hill said.
Zimmerman claims Martin confronted him after the neighborhood watch leader had given up searching for him and was walking back to his truck. But there doesn't appear to be a place to hide in the area where Zimmerman says Martin suddenly appeared, Hill pointed out.
Criminal defense attorney Blaine McChesney, who also is not involved in the case, said he found parts of Zimmerman's re-enactment difficult to envision, such as his account of how he was able to reach for his gun with Martin on top of him. Zimmerman said he got on top of Martin after the shooting to restrain him.
"I also find it strange that Zimmerman would have attempted to use both his arms to hold Martin facedown, re-holstering his firearm, given those circumstances," McChesney said. "Once out from under Martin's alleged attack, it would have been more logical to hold Martin at gunpoint from a few feet away until police arrived."
In the interrogation recording, Sereno told Zimmerman three days after the shooting that Martin was a "good kid, mild-mannered kid."
Sereno told Zimmerman that Martin, an athlete with an interest in aeronautics, was "a kid with a future, a kid with folks that care." The detective said Martin only had a bag of Skittles and an iced tea on him when he died.
"Not a goon," Sereno said.
He asked Zimmerman to explain why he doesn't have bruises on his body or broken ribs. The two dozen punches Zimmerman claims he took are "not quiet consistent with your injuries," Sereno said.
Martin's parents' attorney Ben Crump couldn't immediately be reached for comment. But Crump said on his Twitter feed, "Everyone should review Zimmerman's objectively written statement in comparison to the 911 tapes which were previously released."
Crump did not elaborate.
Zimmerman called police after spotting Martin walking around the neighborhood and the dispatcher told him not to follow the teen. For reasons that are still unclear, Zimmerman kept up his pursuit, even though a dispatcher told him not to.
Zimmerman's second bond hearing will be June 29. His $150,000 bond was revoked earlier this month after prosecutors said Zimmerman and his wife, Shellie, misled the court about how much money they had available for bail. Shellie Zimmerman was charged last week with making a false statement.