COLUMBIA, Mo. -

The United States Attorney's Office announced Tuesday no federal action will be taken in the case of Brandon Coleman's death.

The U.S. Attorney's Office says they opened a preliminary investigation at the request of the NAACP when prosecutors in Boone County decided not to file charges in Coleman's death.

Coleman, 25, was killed May 19, 2013 in the 500 block of N. Ann Street in Columbia. Witnesses say Dustin Deacon shot and killed Coleman following an argument.

The NAACP as well as members of Coleman's family thought racial prejudice played a role in his death. Coleman was black and the shooter is white

Officials think the gunman was not guilty because he acted in self-defense. Prosecutor Dan Knight ruled that the shooter was justified in shooting Coleman under Missouri's self-defense laws.

"Based on the evidence, the law and my ethical responsibilities as a prosecutor, I could not move forward with this case," Knight told ABC 17 News in Oct. 2013.

A spokesperson for the U.S. Attorney's Office says the office, the FBI and the Department of Justice's Civil Rights Division examined evidence in the case and ruled that no federal action is warranted.

Therefore, no criminal charges will be filed and no federal civil action will be pursued.

“It is the policy of the Department of Justice that we shall not respond to questions about the status or existence of an investigation," Tammy Dickinson, United States Attorney for the Western District of Missouri, said in a statement. "However, due to the substantial publicity received by the allegations in this case, and in light of the fact that the request for our office to investigate became a matter of public concern, I have determined that this release of information is in the public's interest.

Winona Coleman-Broadus, mother of Brandon Coleman, told ABC 17 News she still believes it was a racially motivated crime.

"I'm upset," she said. "I'm very upset. I'm on an emotional roller coaster. I'm angry, I'm disappointed, I'm hurt and I'm very disappointed in our legal system."