(Creative Commons)

In the final moments of Martin's life, the teen was on the phone with his girlfriend when he was gunned down.  Benjamin Crump, the family's lawyer, said a log of the conversation shows the teen was the victim of a race-related act of violence, according to USA Today.

In an affidavit from the girlfriend, whose identity is unknown, said Martin grew suspicious of Zimmerman on his walk home from a convenience store in Sanford, FL.

From USA Today:

"He then began walking again, when he tells her, according to Crump, "I think this dude is following me."

"She tells him, 'baby, be careful, just run home,' " Crump said.

According to the girl, Trayvon says, "I think I lost him" then moments later says, "He is right behind me again. I'm not going to run, I'm going to walk fast."

Crump said "she hears another voice, 'What are you doing around here?' Trayvon says, 'Why are you following me?' " At that point, according to the girl, Travyon is pushed and his voice changes.

"She hears the altercation, suddenly, someone just hit the phone, because that's the last she hears," Crump said. She did not hear the shooting."

Phone records of Zimmerman's 911 call moments prior to the shooting capture him saying what is believed to be "f--ing coons."  Zimmerman said he fired the shots in self-defense and was not charged, according to ABC News.

Crump said the phone records contradict Zimmerman's claims that Martin was "high" and involved in suspicious activity.

"It's what Zimmerman wants you to believe so  he can justify killing this kid in cold blood," said Crump.

The shooting sparked outrage in the community and across the nation.  An online petition at Change.com asked for local authorities to prosecute Zimmerman and accumulated over 500,000 signatures, according to the Washington Post.

A federal investigation of the incident will assess local law enforcement's response and whether Martin was targeted because of his race, said an unidentified federal official.