US officials are investigating the fatal shooting of an unarmed black Florida teenager by a white neighborhood watch volunteer that has sparked national outrage. Trayvon Martin, 17, was shot to death February 26 in a gated community in central Florida by a neighborhood watch captain, George Zimmerman, who later was released by police after claiming he acted in self-defense. Benjamin Crump, the lawyer for Trayvon Martin\'s family, said Tuesday Martin had put on a hoodie after getting caught in the rain and was not aware he was being followed by Zimmerman. \"He\'s just a kid trying to get home from the store and get out of the rain, that\'s it, nothing else,\" Crump told a news conference. He said Martin\'s 16-year-old girlfriend was on the phone with him at the time and heard most of the altercation. \"What Zimmerman said is completely contradicted by the phone log,\" Crump added, urging authorities to arrest the neighborhood watchman for killing Martin \"in cold blood.\" Speaking to ABC News, the girlfriend recalled that Martin \"said this man was watching him, so he put his hoodie on. He said he lost the man.\" \"I asked Trayvon to run, and he said he was going to walk fast. I told him to run, but he said he was not going to run,\" added the girlfriend, who was not identified. The Justice Department said its Civil Rights Division plans to \"conduct a thorough and independent review of all of the evidence.\" The division examines cases in which discrimination on the basis of race, sex, disability, religion, and national origin are suspected. The FBI is also investigating the racially charged killing. Martin\'s case is heading to a grand jury, where an economically and racially diverse group of citizens will decide whether to bring charges against Zimmerman on April 10, according to the local state attorney\'s office. \"I share in the desire of the family and the community to accurately collect and evaluate all the facts surrounding the tragic death of Trayvon Martin,\" Norman Wolfinger, state attorney for Brevard and Seminole counties, said in a statement. Protests by human rights activists and non-governmental organizations followed the February shooting in a gated community in the central Florida town of Sanford. Protesters are demanding the arrest of the volunteer guard. Martin was walking home after buying candy at a local convenience store when he was confronted by Zimmerman, identified by local media as a 28-year-old white man of Hispanic origin. Before the shooting, Zimmerman called 911 to say a suspicious person was walking through the neighborhood wearing a hooded jacket on a rainy night. When the 911 operator asked about the race of the suspect, Zimmerman responded that he was black. The 911 operator told Zimmerman not to follow the suspect and to await the arrival of patrol officers. But Zimmerman allegedly shot the young man a short time later, claiming he acted in self-defense. Civil rights advocate Al Sharpton, meanwhile, is meeting with Sanford community leaders and residents to discuss how the investigation will proceed.