By Shelby Lin

(CNN) - It's a case that has burst into the national spotlight.

An unarmed African American teen shot dead by a neighborhood watch volunteer as he walked through a neighborhood to watch basketball with his father.

Now federal officials will join Florida in looking into what happened to Trayvon Martin.

An attorney for Trayvon Martin's father gave a news conference Tuesday with new developments. The teen was on his cell phone with a girlfriend in the moments before he died.

"Arrest George Zimmerman for the killing of Trayvon Martin in cold blood today. Arrest this killer," said family attorney Benjamin Crump.

The young woman, Martin's friend, who did not want her name used, spoke to ABC.

"He said this man was watching him so he put his hoodie on to run from him," said Crump. "Then the man said 'What you doing around here?' then somebody pushed Trayvon because the headset just fell."

That contradicts what George Zimmerman, a member of the neighborhood watch group, told police. He told them he acted in self defense.

Zimmerman has not been arrested or charged.

Zimmerman hasn't been heard from publicly, but his family says he is not a racist, is of mixed race himself, and he has recently gotten death threats.

Also, the police report finds that Zimmerman was bleeding in his nose and on the back of his head when they arrived.

The case, which has fueled public outcry in the racially mixed community, is going to a grand jury in Seminole County, Florida.

Late Monday night the Justice Department decided to investigate.

Read or Share this story: