The American Civil Liberties Union on Tuesday told a House panel that local law enforcement's response to the death of Trayvon Martin showed why it was necessary to have federal laws against racial profiling.

"The killing of Trayvon Martin has once again laid bare the reality that, too often in our nation’s history, police actions have been motivated by racial bias and that crimes with an undeniable racial motive have too often been overlooked or swept under the rug," Dennis Parker of the ACLU told a House forum hosted by Democrats.

On February 26, self-appointed neighborhood watchman George Zimmerman allegedly pursued and shot Martin in Sanford, Florida. When police arrived on the scene, Zimmerman claimed that he shot and killed the African American teenager out of self-defense, which allowed him to benefit from Florida’s “Stand Your Ground” law. Zimmerman was not arrested.

Parker said the Sanford Police Department had a "disturbing history of responses to incidents that involve African Americans."

In 2006, two private security guards shot a black teenager in the back with a shotgun, killing him. They were released without charges. In 2010, the son of a Sanford Police Department lieutenant assaulted a homeless black man outside a bar. He was also released without charges, Parker said.

"While the alleged conduct of private citizens like George Zimmerman is beyond the scope of the End Racial Profiling Act and the Department of Justice Guidance Regarding the Use of Race by Federal Law Enforcement Agencies -- the actions of the police and other government officials in response to that shooting is not," Parker continued.

"In addition to investigating to what degree race was a factor in the law enforcement response to Trayvon’s death, Congress should pass the End Racial Profiling Act which among other things provides training to help police avoid responses based on stereotypes and false assumptions about minorities and urge the administration to strengthen the Department of Justice Guidance Regarding the Use of Race by Federal Law Enforcement Agencies."

Sen. Ben Cardin (D-MD) introduced the End Racial Profiling Act in 2011, but the bill has not yet been taken up by the Senate Committee on the Judiciary.

The bill would prohibit law enforcement agents from stopping, investigating, arresting, or detaining an individual based on his or her race, ethnicity, religion, or national origin. It would also mandate training on racial profiling issues as part of federal law enforcement training, and require local and state departments to adopt measures to eliminate racial profiling as a condition of receiving federal funding.