The parents of Trayvon Martin, a 17-year-old shot and killed in Florida Feb. 26, want the FBI to investigate the case.

At a press conference in Orlando Friday, Martin's parents, Tracy Martin and Sybrina Fulton, announced that they no longer trust the Florida police currently on the case. They accused the police of botching the investigation and criticized them for not arresting George Zimmerman, 28.

Do we really believe that if Trayvon Martin would have pulled the trigger, he would not be arrested? said Benjamin Crump, their attorney. This is obviously a cover-up, and we need a sweeping overhaul of the Sanford Police Department.

 Zimmerman told the police he shot Martin in self-defense, according to The Associated Press. Zimmerman called 911 to report Trayvon as a suspicious person and was told to stay in his car and an officer would be there soon.

However, before police arrived, Zimmerman shot and killed Trayvon.

Trayvon was visiting his father, who lived in the neighborhood, from Miami. He had left during half-time of the NBA All-Star Game he and his father were watching to go to a local convenient store. On his way back to his father's house he was shot.

[Trayvon] was stereotyped for some reason, said Crump, reported the Huffington Post. Why was Trayvon suspicious?

Police have refused to release tapes or transcripts of the 911 call prior to Trayvon's death, according to CBS News.

What happened between him being confronted, up to the point where he got shot, nobody knows but him and that guy, Tracy, told the Post. I'm looking for justice for my family. I want answers but I don't have any to give--not for his mother, his brothers or sisters. We don't have nothing, but we want answers.

Zimmerman's father delivered a letter to the Orlando Sentinel Thursday saying his son is not a racist and has had to leave his home after receiving death threats. The letter claims Zimmerman is Hispanic and grew up in a multi-racial home, making him the last to discriminate.

At no time did George follow or confront Mr. Martin. When the true details of the event became public, and I hope that will be soon, everyone should be outraged by the treatment of George Zimmerman in the media, the letter said.