Trayvon Martin's parents renewed their calls for calm Wednesday as a law enforcement official in Florida said that charges would be filed against neighborhood watch volunteer George Zimmerman in their son's shooting death.
The charges were expected to be announced later in the day and the arrest of Zimmerman, who has said he shot in self-defense, also was expected soon, according to the official. He spoke to The Associated Press on condition of anonymity because he wasn't authorized to publicly release the information.
Reports of the impending charges and arrest were trickling out of Florida as Martin's parents held a previously scheduled news conference at a Washington convention by a group founded by the Rev. Al Sharpton.
The parents, their attorney and Sharpton declined to answer questions about the reports at that event, saying they needed to confirm them.
Zimmerman has not jailed or charged since the Feb. 26 shooting.
The family and their attorney, Ben Crump, renewed calls for calm in the case. "We don't need anybody taking these matters into their own hands," Crump said.
"I know beyond a shadow of a doubt, justice will be served" in her son's death, said Martin's mother, Sybrina Fulton.
Sharpton said while everyone is angry, no one can be more angry than Martin's parents, "and if they can operate with dignity, we can operate with dignity," Sharpton said.
Earlier, Attorney General Eric Holder said he would take appropriate action if evidence of a civil rights crime is found to have been committed in the shooting.
The Justice Department launched an investigation of the Martin killing three weeks ago.
"I know that many of you are greatly _ and rightly _ concerned about the recent shooting death of 17-year-old Trayvon Martin, a young man whose future has been lost to the ages," Holder told the 14th annual convention of the National Action Network, three days of discussion on race issues.
"If we find evidence of a potential federal criminal civil rights crime, we will take appropriate action," said the attorney general. "I also can make you another promise: that at every level of today's Justice Department _ preventing and combating youth violence and victimization is, and will continue to be, a top priority."
The attorney general says that Justice Department officials including Tom Perez, the assistant attorney general for the civil rights division, and U.S. Attorney Robert O'Neill from Florida have traveled to Sanford to meet with the Martin family, members of the community and local authorities.
He says representatives from the department's Community Relations Service are meeting with civil rights leaders, law enforcement officers and residents to address community tensions.
Zimmerman has said he shot Martin in self-defense after following the teenager in a Sanford, Fla. gated community outside Orlando. He said he was returning to his truck when Martin attacked him and that he shot the unarmed teen during the fight. He wasn't arrested partly because of Florida's "stand your ground" self-defense law.
The lack of an arrest led to protests across the nation and spurred a debate about race and the laws of self-defense. Zimmerman's father is white and his mother is Hispanic. Martin was black.
On Tuesday, Zimmerman's attorneys announced they were no longer representing him and that they had not heard from him since Sunday, although he had contacted talk show host Sean Hannity and the special prosecutor.
Also Wednesday, New York City Mayor Michael Bloomberg and leaders of African American organizations announced a national campaign against "stand your ground" self-defense laws.
Bloomberg told a National Press Club news conference that the "stand your ground" laws make it more difficult to prosecute people who use guns and say they used them in self-defense. This law "justifies civilian gun play," he said.
"You just cannot have a civilized society where everybody can have a gun and make their own decisions as to whether someone is threatening or not," Bloomberg said at another event.
AP reporter Stacy A. Anderson contributed to this report from Washington.