Sanford , Florida ( CNN ) -- Federal prosecutors and the FBI have opened an investigation into the killing of an unarmed teen by a neighborhood watch volunteer in Florida . The death drew protesters Monday to the courthouse in Seminole County , north of Orlando , to demand justice for Trayvon Martin , the 17-year-old who was shot and killed last month while walking back to his father 's fiancee 's house in Sanford . The African-American teen 's parents said Monday that they believed race was a factor in their son 's death , and the Congressional Black Caucus had called for a federal investigation , saying local police have shown `` blatant disregard for justice . '' Late Monday , the Justice Department said it would dispatch officials to Sanford to investigate and `` to address tension in the community . '' `` The department will conduct a thorough and independent review of all of the evidence and take appropriate action at the conclusion of the investigation , '' Justice Department spokeswoman Xochitl Hinojosa said in a written statement . `` The department also is providing assistance to and cooperating with the state officials in their investigation into the incident . '' Florida Gov . Rick Scott also weighed in Monday evening , noting that the case has `` caused significant concern within the Sanford community and the state '' and asking the Florida Department of Law Enforcement to provide `` any assistance necessary '' to local investigators . The man who shot Trayvon , George Zimmerman , has not been charged . He told police he shot the teen in self-defense , and police say they have no evidence to refute his story . Trayvon 's father , Tracy Martin , told CNN 's `` Anderson Cooper 360 '' that his son 's death was `` a matter of profiling . '' `` I think that 's an issue that Mr. Zimmerman himself considers as someone suspicious -- a black kid with a hoodie on , jeans , tennis shoes , '' Martin said . `` Thousands of people wear that outfit every day , so what was so suspicious about Trayvon that Zimmerman felt as though he had to confront him ? '' And the slain teen 's mother told NBC 's `` Today '' show that the neighborhood watch captain `` was out there reacting to the color of his skin . '' `` My son was n't doing anything but walking on the sidewalk , and I just do n't understand why this situation got out of control , '' Sybrina Fulton said . CNN has made numerous attempts to contact Zimmerman , who is Hispanic , but have been unsuccessful . In a statement to the Orlando Sentinel , his father says Zimmerman grew up in a multiracial family and has moved out of his home after receiving death threats . And in announcing the federal probe , Hinojosa cautioned that bringing a civil rights case requires the government prove `` that a person acted intentionally and with the specific intent to do something which the law forbids -- the highest level of intent in criminal law . '' At the Seminole County courthouse , a handful of student protesters and a law professor from Florida A & M University met with a representative of the state attorney 's office to discuss the ongoing investigation while protesters demanded Zimmerman 's arrest . Many carried signs in remembrance of Trayvon . `` Gone but not forgotten , '' read one that had a picture of the young man wearing a football uniform . `` No justice for Trayvon . No peace for Sanford ! '' read another . Assistant State Attorney Pat Whitaker told the students it would take several weeks to look at the case , but that the `` investigation of the Sanford police needs to be greatly supplemented , '' Jasmine Rand , the FAMU professor , said after the meeting . The state attorney 's office also said a voice analysis would be conducted on 911 calls from the night of the shooting to determine who was yelling for help , students said . Zimmerman , 28 , called police around nightfall on February 26 to report a suspicious man in his neighborhood . `` Something 's wrong with him . Yep . He 's coming to check me out , '' Zimmerman told a police dispatcher in a 911 call released Monday . `` He 's got something in his hands . I do n't know what his deal is . Send officers over here . '' The teen started to run , Zimmerman reported . When he said he was following , the dispatcher told him , `` We do n't need you to do that . '' Shortly afterward , neighbors began calling 911 to report a fight , then a gunshot . By the time police arrived , Trayvon lay dead . He was carrying a bag of Skittles and an iced tea that he had purchased at a nearby convenience store , and was headed back to his father 's fiancee 's home . Martin said he 's `` positive '' that his son 's voice that can be heard screaming for help in the neighbors ' calls . `` It 's heartwrenching , because those actually were my son 's last words , '' he said . `` And to hear his last words being cries of help , is devastating . It tears me apart as a father . '' CNN 's Roland S. Martin , Rick Martin , John Couwels , Vivian Kuo and Terry Frieden contributed to this report .
The Justice Department has launched an investigation into the death of Scott Martin . Florida Alzheimer 's asks the state to assist probe as well . A neighborhood watch ##man tells police he shot the teen in self - defense . The 17-year - old was not armed when he was killed last month in Florida .