Three days after George Zimmerman killed an unarmed teenager and went home free, he had a predicament: The lead detectives investigating the shooting seemed to no longer believe his story.

Sanford Police Det. Chris Serino told Zimmerman in a series of interviews that day that he was a “good guy,” but that there were holes in his story, including minor injuries that did not match the beating he said he received at the hands of a “child” who carried candy.

Zimmerman repeatedly told police that Trayvon Martin sucker-punched him, tried to suffocate him and bashed his head into the concrete to the point it felt his “head was going to explode.” He said Trayvon tried to take his gun from him before saying: “You’re going to die tonight, motherf-----.”

But Serino wondered why Zimmerman’s skull wasn’t fractured, why he didn’t know the street names of a tiny neighborhood where he’d lived for three years and why he had no defensive wounds on his hands. Serino got him to acknowledge what Trayvon’s parents and lawyers have said all along: that Zimmerman got out of his car that night not so much to check for an address to give police, but to find out where the teen went.

“That was a kid with a future, a kid with folks that care. Not a goon,” Serino said. “In his mind’s eye, he perceived you as a threat. He has every right to defend himself.”

Tapes released Thursday of questioning between Zimmerman and Sanford police underscore a sharp contrast between the public statements made by the Sanford Police Department the weeks following Trayvon’s killing and the conversations that went on internally. They offer the first glimpse of a man who told detectives that he takes medication for attention deficit hyperactivity disorder, and who at one point became the most controversial man in America. The interrogations also reveal that detectives were troubled by a man with a history of inserting himself into law enforcement matters who did not have the training to determine what a “suspicious” person should look like.

Zimmerman detailed a harrowing night when he said a stranger accosted him for no reason and allegedly threatened to kill him. At least twice witnesses failed to come to his aid. One of the first things Zimmerman said to Det. Doris Singleton: The bad guys always get away.

Hinting that Zimmerman had left something out of his account, Serino asked over and over why Trayvon would have been so enraged as to deck a perfect stranger. Zimmerman, he suggested, had chased him.

“You wanted to catch him. You wanted to catch the bad guy, the f-----g punk who can’t get away,” Serino said, referring to words Zimmerman used on his call to police.

At one point, Zimmerman answered: “I wasn’t following him; I was just going in the same direction he was.”

Serino retorted: “That’s following.”

Zimmerman is facing a second-degree murder charge for the killing. The arrest came six weeks after the shooting and a short time after a widely criticized investigation was handed over to other agencies. Despite Serino’s misgivings — and the detective’s recommendation that Zimmerman be charged with manslaughter — Sanford Police publicly stated that there was no probable cause to make an arrest, so the politically charged case was handed over to the Florida Department of Law Enforcement.

Defense attorney Mark O’Mara on Thursday posted statements — eight on audio, two on video and one written — in which Zimmerman gave police his version of the night’s events. The tapes show he was calm, sometimes dazed, and neither upset nor remorseful. He was consistent in his account that a “suspect emerged from the darkness” and punched him so hard in the nose that he fell.

Just a day after the shooting, Zimmerman cooperated with police and returned to the gated community as they shot video of him re-enacting the fight. He described where he first saw Trayvon, how he followed after him and how Trayvon set upon him and tried to seize his gun.

Trayvon, he said, “wailed” on his head so hard it felt like he was being hit with bricks. Zimmerman said he grabbed the gun first and “fired one shot,” causing Trayvon to kind of sit back and say: “You got me. You got it.”

Simmerman indicated that he didn’t realize Trayvon was shot at this point, though it was point-blank range.

“I didn’t think I hit him,” Zimmerman told police during the re-enactment. “I thought he was just saying: ‘I know you have a gun now. I heard it. I give up.’”

That night Zimmerman gave a detailed verbal statement to a police official who used voice-analyzing software to help determine the veracity of his statements.

The videos mark the first time the public can see and hear how Zimmerman described the lead-up to his confrontation with Trayvon and what led him to shoot the Miami Gardens teen on that rainy evening at a gated community in Sanford. They show him on the day after the killing wearing two mid-sized butterfly bandages on the back of his hand and a bandage between his eyes.

Two days later, a police video showed he wore a much larger bandage.

On the tapes released Thursday, Zimmerman said Trayvon “appeared out of nowhere.”

“You got a problem?” Zimmerman said Trayvon asked. In another statement, he phrased it, “You got a f---ing problem, homie?”

“I said no, I don’t have a problem,’” Zimmerman said he responded. He said he fumbled for his cellphone and thought it was in his pants. But it was in his jacket pocket.

“He just punched me in the nose. And I fell backwards and to the side, and somehow I wound up on my back. He ended up on top of me. And he just kept punching my face. And my head. And I was screaming for help,” Zimmerman said.

“Shut the f--- up,” Trayvon said as he kept punching him, Zimmerman recounted.

“He slammed my head into the concrete,” Zimmerman said. “Each time it felt like my head was going to explode… And then he covered my nose with one hand and my mouth with the other one. And he told me shut the f--- up. And I couldn’t breathe. I was suffocating. And all I could think about was I didn’t want him to keep slamming my head against the concrete.”

Serino played a 911 tape for Zimmerman that recorded the scuffle, and questioned how he could be screaming for help so loud with a hand over his mouth. In many instances during the interview, Serino talks but either hardly gives Zimmerman a chance to respond or Zimmerman’s answers are not audible.

Another investigator present as Serino played the police emergency tapes accused Zimmerman of misleading her the night of the killing, when he claimed that he got out of his car only to check for an address.

“You decided to get the address a fraction of a second after you said, ‘Oh s--t. He’s running?’” Det. Singleton said. “And it sounds like you’re running too.”

Zimmerman said he wasn’t running; it was just windy.

Legal analysts who are watching the case closely said the reenactment video benefits Zimmerman, because it shows him telling his self-defense account clearly and convincingly.

“For George Zimmerman, this is one big positive,” said Harvard Law Prof. Alan Dershowitz, who has had a public scrap with the prosecutor Gov. Rick Scott appointed to the case, Angela Corey. “If it’s admitted in court, he is not subject to cross examination and then that makes it harder for the prosecution.”

Dershowitz said he’s not sure if the defense, however, can submit the video statements as evidence. The prosecution might have to do that. And it probably won’t, he said, because it makes Corey look bad.

Corey and Dershowitz have had a public battle over what he considers a grossly overcharged case and an unethical probable-cause affidavit filed in court, which failed to mention Zimmerman’s broken nose and scraped head.

The affidavit Corey filed “knowingly tells a false story,” Dershowitz said. “She overcharged. But that’s her reputation: She over-charges. If Rick Scott wanted to avoid a riot and make sure that George Zimmerman was overcharged, he picked the right prosecutor.”

Cheney Mason, an Orlando criminal defense attorney who helped successfully defend accused “tot-mom” killer Casey Anthony last year, said the reenactment video is just more proof that “Zimmerman shouldn’t have been charged in the first place.”

“If a jury sees this tape, this case is over,” Mason said. “George Zimmerman will walk as a free man. But it shouldn’t even get to a jury. A judge, if he has the political courage, should throw this case out.... Zimmerman has made a strong case that he was fighting for his life.”

Trayvon’s family’s attorney, Benjamin Crump, said he noticed several inconsistencies between Zimmerman’s written statement and what could be heard on his call to police:

“It is clear to us and should be clear to everyone why Angela Corey charged him with second degree murder.”

.Crump was with Trayvon’s parents in New Orleans at a journalism convention speaking about the shooting.

Tracy Martin and Sybrina Fulton, along with Al Sharpton, spoke at the National Association of Black Journalists convention about the importance of Trayvon’s case exploding into a national discussion about racial profiling and Florida’s controversial Stand Your Ground law.

Neither parent has seen or heard the police statements and audio made public on Thursday. And Sybrina Fulton never plans to look.

"I don’t want to see it. I don’t want to relive it," she said. "It would be too hard."

She talked about missing her son’s smile and driving him to school. “He was loving,” she said. “He used to kiss me everyday."

His father, whom Trayvon was staying with at the time of the shooting, will review the case, no matter how painful.

“As a father, I have to look at the stuff, because I am looking for the answers to why my son’s life was taken,” he said. “I know it will be troubling, but I have to see it for myself.”

Staff writers Audra D.S. Burch and Janey Tate contributed to this report.