(ABC News) -- "He took my head and slammed it against the concrete several times, and each time I thought my head was going to explode and I thought I was going to lose consciousness," George Zimmerman told police the day after he shot and killed Trayvon Martin.
"I started screaming for help," but Martin pressed his hands over Zimmerman's mouth and nose, he said. "He told me to shut the f&#k up, and I was suffocating."
Zimmerman told police he was lying on the ground, but his head was on the concrete.
"I didn't want him to keep slamming my head on the concrete so I kind of shifted. But when I shifted my jacket came up…and it exposed my firearm. That's when he said you are going to die tonight. He took one hand off my mouth, and slid it down my chest. I took my gun aimed it at him and fired."
The latest and most detailed account yet of what happened in Sanford, Fla., on Feb. 26 comes from a voice stress test that Zimmerman passed, along with a video re-enactment, a handwritten statement and audio interviews conducted in the days after the shooting by investigators.
The material was released by Zimmerman's attorney today on the website gzlegalcase.com, a website managed by the Zimmerman defense team.
The relatively consistent statements portray a man trying to convince investigators that he was in a life and death struggle that left him with little choice but to kill the unarmed teenager.
The documents also show that in the days following the shooting, the lead investigator was not accepting Zimmerman's version of events and recommended that charges be filed against Zimmerman.
"I shot him, and I didn't think I hit him because he sat up and said, 'Oh you got me. You got me, you got it,'" said Zimmerman during a nearly 20-minute re-enactment shot by investigators at the scene of the shooting the next day.
Watch George Zimmerman's Lie Detector Test
In the video Zimmerman, 28, gives a blow by blow description of how the fight began and depicts Martin as the aggressor, a key point as his legal team builds his defense on Florida's controversial "stand your ground" law.
Zimmerman said he was driving to buy groceries when he spotted the unarmed teen walking near a house that he knew Martin did not live in and called police to report a suspicious person.
"I just felt like something was off about him…and there's been a history of break-ins ... so I said you know just better to call. I kept driving and I passed him, and he kept staring at me and staring around," Zimmerman said.
Read George Zimmerman's Handwritten Statement
He took investigators to the house where he first spotted the teen and got on the phone with police. At that point he says he lost sight of Martin.
With bandages clearly visible on the back of his head and nose in the video, he took investigators through the neighborhood showing them where he was when the responder told him that he did not have to follow Martin. Zimmerman says by the time of the request he was no longer in his car and wanted to figure out exactly where he was in the subdivision, so that the officer dispatched to the scene could find him.
"I was walking back. I didn't see anything again, came back to my truck and when I got to right about here, he yelled from behind to me."
"He said, 'Yo, you got a problem?' and I turned around and said no I don't have a problem," said Zimmerman.
"I went to grab my cell phone, but I left it in a different pocket. I looked down at my pants pocket, he said, 'You got a problem now' and then he was here and he punched me in the face," said Zimmerman, throwing a punch near his own face to illustrate.
"I think I stumbled and I fell down, he pushed me down, somehow he got on top of me... I was trying to push him away from me. He got on top of me somewhere around here, and that's when I started screaming for help. I started screaming HELP as loud as I could. I tried to sit up. That's when he grabbed me by the head and he tried to slam my head down," Zimmerman said.
"He kept slamming and slamming, and I kept yelling HELP, HELP, HELP as loud as I could," he said.
In the voice stress test video, which begins with a bandaged Zimmerman commenting to an officer on the high price of health insurance as a reason he was hesitant to get treatment the night of the shooting, he later calmly questioned an officer about what she did on the force.
But in a Feb. 29 interrogation, lead investigator Chris Serino openly doubts the story.
"You ever hear of Murphy's law?" asks Serino. "This person was not doing anything bad. You know the name of the person that died?"
"Tavon," responds Zimmerman
"Trayvon," Serino shot back.
"Trayvon Martin" responds Zimmerman.
"Trayvon Benjamin Martin…He was 17…A kid with a future," said Serino. "In his possession we found a can of ice tea and a bag of Skittles. And $40 in cash. Not the goon."
Serino then peppered Zimmerman about if he had any law enforcement experience, and why he deemed Martin suspicious and decided to follow him.
"You know you are going to come under a lot of scrutiny over this, correct?" asks Serino. "Had this person been white would you have felt the same way?"
"Yes," responded Zimmerman.
Serino then questioned the extent of Zimmerman's injuries telling him that they don't seem consistent with someone involved in a life or death struggle. A medical report obtained earlier by ABC News revealed that Zimmerman suffered a broken nose and two lacerations on the back of his head.
Another investigator then asked why didn't he just identify himself as a member of the local neighborhood watch. Both investigators then ask if it was raining outside, and if he decided not to follow Martin after the non-emergency dispatcher asked him to get back in the car why didn't he.
"You wanted to catch him. You wanted to catch the bad guy," said Serino aggressively later in the interview, implying that it was Zimmerman who instigated the altercation.
Lead investigator Serino later recommended that manslaughter charges be brought up against Zimmerman, but Seminole County State's Attorney Norm Wolfinger rejected the request citing a lack of solid evidence. The initial lack of an arrest in the case led to widespread protests, and propelled the case into the national headlines. In April, special prosecutor Angela Corey appointed by Florida Gov. Rick Scott charged Zimmerman with second degree murder.
The Martin family issued a statement today through their lawyer Benjamin Crump.
"When you look at the hand-written statement written by George Zimmerman on the night of the shooting that he did before he talks to lawyers, his words, and take that into consideration with the audio statements, the witness interviews, and the previously released evidence, it is clear to us why Angela Corey charged George Zimmerman with second degree murder," the family said.