SANFORD, Fla. -

The public is getting its first look at potential evidence in the case against George Zimmerman, the neighborhood watchman who shot and killed 17-year-old Trayvon Martin in February.

The state attorney's office on Thursday released 183 pages of documents, plus photos of Zimmerman's injuries and weapon, as well as audio recordings of witness statements.

Included in the document is a request by the Sanford Police Department for a "capias" – or arrest warrant – that would have charged Zimmerman with manslaughter.

The investigator said the altercation could have been avoided if Zimmerman hadn't approached Martin.  The investigator wrote, "Zimmerman can be heard in the background crying for help," and he said "the encounter between George Zimmerman and Trayvon Martin was ultimately avoidable by Zimmerman if Zimmerman had remained in his vehicle and awaited the arrival of the law enforcement."

The investigator added that Zimmerman could have identified himself to Martin as a "concerned citizen."

Photos of Zimmerman with visible injuries were also included in the release of information, showing what appears to be a broken nose and dried blood on his head. A paramedic report says Zimmerman also had a 1-inch laceration on his head and forehead abrasion.

Witness audio statements were also included, with one of the most controversial from "witness 9" in an undated interview.

"I just would hate to see that be the case here, because I know that about him. I don't know what happened. I don't know it all, who this kid was or anything else, but I know George," the witness said. "And I know that he does not like black people and he would start something. He's a very confrontational person. It's in his blood. Let's just say that -- and I don't want this poor kid and their family to just be overlooked."

In another audio witness statement, Martin's girlfriend, who was on the phone with Martin, said she heard Trayvon Martin say, "Get off, get off," before the phone went dead. She also described him as sounding "scared" and told him to run.

FBI audio specialists couldn't identify who was screaming in the background of one 911 call because of the quality of the audio. The audio analysts also couldn't conclude if Zimmerman said a racial slur or not. But Zimmerman's father, Robert, said that the voice calling for help was his son.

"That is absolutely, positively George Zimmerman. Myself, my wife, family members and friends know that is George Zimmerman, there's no doubt who's yelling for help."

An autopsy report shows Martin had THC in his system the night of the shooting. THC is the psychoactive ingredient in marijuana. The autopsy was conducted the day after the teenager was shot dead. Toxicology tests found elements of the drug in the teenager's chest blood -- 1.5 nanograms per milliliter of one type (THC), as well as 7.3 nanograms of another type (THC-COOH) -- according to the medical examiner's report.

There was also a presumed positive test of cannabinoids in Martin's urine. It was not immediately clear how significant these amounts were.

Martin had $40.15, Skittles, a red lighter, headphones and a photo pin in his pocket, according to the police report. He had been shot once in the chest and was pronounced dead at the scene.

Martin was walking to his father's girlfriend's home from a 7-Eleven store in February when Zimmerman called police to report him as suspicious.  A confrontation ensued, and Zimmerman fatally shot Martin in the gated community of townhomes in Sanford.

Zimmerman has claimed self-defense and has entered a not guilty plea.
The lack of an arrest in Martin's death for 44 days inspired protests nationwide.

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