MIAMI -- The NAACP and other civil rights groups, angered by a Florida jury's acquittal in the shooting death of Trayvon Martin, turned up the pressure Sunday on the U.S. Justice Department to pursue federal criminal charges against the man who killed him, George Zimmerman.In a statement issued later in the day, the Justice Department said its civil rights division, the FBI and the U.S. Attorney's Office for the Middle District of Florida are evaluating evidence generated during a federal inquiry opened last year, in addition to evidence and testimony from the state trial."Experienced federal prosecutors will determine whether the evidence reveals a prosecutable violation of any of the limited federal criminal civil rights statutes within our jurisdiction," the statement said. It said the DOJ will determine "whether federal prosecution is appropriate in accordance with the department's policy governing successive federal prosecution following a state trial."The criminal civil-rights laws at the department's disposal have been used to make such cases in the past.Among them: the federal prosecution of a group of Los Angeles police officers after they were acquitted in state court of the brutal beating of Rodney King in 1991, which sparked riots in that city. Two of the four officers were eventually convicted by a federal jury of violating King's civil rights under "color of law" -- that is, beating him up in their capacity as cops. That law applies only to those in law enforcement, however, and Zimmerman is a civilian.In his case, it's possible the department might consider using a different type of civil-rights law: the federal hate-crime statute. As in the King case, the double-jeopardy clause of the U.S. Constitution does not prohibit such a federal prosecution after Zimmerman's state acquittal. Legal experts said it would be a formidable challenge for Attorney General Eric H. Holder Jr. to make a hate-crime case against Zimmerman under U.S. civil rights laws, because Florida jurors found Zimmerman not guilty of second-degree murder and manslaughter in Martin's death.Jurors found that prosecutors failed to prove the more serious second-degree charge that Zimmerman, the neighborhood watchman at a Sanford gated community, possessed "ill-will," "hatred" or "spite" in the fatal shooting of Martin. Instead, the six female jurors found that Zimmerman acted in self-defense.Consequently, experts said, it would be legally inconsistent for the Justice Department to consider filing criminal charges against Zimmerman under the federal Shepard-Byrd Hate Crimes Prevention Act of 2009. Generally, that law prohibits someone from "willfully causing bodily injury" because of race, color, religion or national origin."If the state jury had been persuaded beyond a reasonable doubt that Zimmerman caused bodily harm to Trayvon Martin because of Martin's race, it would have almost certainly convicted Zimmerman of second-degree murder, which requires proof of 'ill-will' or 'malice,'" said Scott Srebnick, a prominent federal criminal defense attorney in Miami. "So, to bring a federal civil-rights prosecution against Zimmerman, the attorney general would essentially be second-guessing the state jury's verdict, as opposed to vindicating a different or broader federal interest."I find it doubtful that the attorney general will pursue a prosecution on a civil-rights theory simply out of displeasure with the state jury's verdict," Srebnick said.Brian Tannebaum, a Miami defense attorney and past president of the Florida Association of Criminal Defense Lawyers, agreed."People are comparing this case to Rodney King, where there was a federal prosecution after a state acquittal, but the difference there was there were witnesses, specifically the video everyone still remembers," Tannebaum said, referring to a videotape of the police beating."Zimmerman was a failed prosecution from the beginning -- where the only witness [Zimmerman] had the right to remain silent [by not testifying] -- and I don't think the federal government will try again," Tannebaum said.The day after the verdict, Trayvon's parents, Sybrina Fulton and Tracy Martin, spoke with their attorney, Benjamin Crump, about what happens next -- possibilities include not only a federal prosecution, but also a wrongful-death case against Zimmerman in civil court."Sybrina cried and prayed last night in Miami, but she also made a decision that she is not going to let this verdict define the legacy of her son, Trayvon Martin," Crump said. "She and Tracy are ready to roll up their sleeves and get to work using their foundation to make sure this never happens to another child. At the same time, they are still trying to understand the verdict and then they will be making a decision about pursuing the case in other ways legally."Meanwhile, the NAACP, in a statement issued by President Benjamin Todd Jealous, said the civil rights group was "not done demanding justice for Trayvon Martin."The group's public pressure on the Justice Department puts Holder, the nation's first black attorney general, in the difficult position of making a daunting decision on a controversial case that has riveted the nation's attention and ignited renewed debate about racial profiling.The not-guilty verdict in the Zimmerman murder trial served as a call to action for participants of the 104th NAACP National Convention this week in Orlando, but it wasn't Zimmerman's name that was being invoked Sunday in keynote speeches and talked about in the expansive halls of the Orange County Convention Center. The 4,000-plus association members are focused on the unarmed teenager and what they could do to ensure a death like his is not repeated."Like you, I have a lot of questions as it relates to the verdict and what it means to be young and black in this country," Sammie J. Dow, national director of the NAACP's Youth and College Division, said Sunday to about 200 young people gathered from across the country. "If there's ever been a time that we needed to act, that time is now."We need to work, and work like never before, to put laws in place in our local communities to make sure there's not another Trayvon Martin," he said, the crowd rising to its feet. "You can be 17 years old, going to the store to buy candy and tea. And on your way back to your house, you can be shot and killed. And this country tells us that's OK."Nobody else is going to care if Youth and College doesn't care. Nobody else is going to act if we don't act. If not us, who? If not now, when? We are the most powerful force this country has ever seen. We are young, gifted and unapologetically black. I am Trayvon Martin. You are Trayvon Martin. And we have to act."In the audience for Dow's speech was 13-year-old DeTronia Irby, who came from Detroit to attend his first NAACP convention."It makes me sad that after all these years, people still aren't treated equal," the ninth-grader said. "Justice is needed, because I know the trial outcome] makes me feel less safe."DeTronia said he doesn't want to just talk about change - he wants to act on it. He said he may use his Twitter account as a way to unite people in his community."I'm going to start organizing my friends and stuff," DeTronia said. "It's easier to make changes when you're working together."Earlier in the Youth and College session, speaker Alethea Bonello touched on the Zimmerman case during an opening prayer."We shall not be moved by six jurors. We shall not be moved by a slick-talking defendant. We will stand our ground," said Bonello, a former Southeast regional director for the NAACP youth division."Before we knew Trayvon Martin, we knew Martin Lee Anderson," she said, referring to a 14-year-old black youth whose 2006 death at a Panama City juvenile-detention boot camp -- and subsequent demonstrations and marches on his behalf -- prompted the Florida Legislature to close the state's five juvenile boot camps and resulted in a $2.4 million settlement from Bay County to Anderson's family."We've come here for fun, and we've come here for fellowship, but we're also here to do work," Bonello said to the Youth and College crowd in front of her. "Remember the young people who came before you for the civil rights movements in Tallahassee and Jacksonville and Miami."The ACLU of Florida also expressed disappointment and frustration over the acquittal verdict."The tragedy in this case is that the needless death of a 17-year old is yet another example of the deadly consequences that come from seeing the world through racial stereotypes," ACLU executive director Howard Simon said in a written statement."The confrontation that resulted in Trayvon Martin's death occurred because, in a neighborhood that had experienced recent burglaries, George Zimmerman saw a young black male as a threat to his community," Simon said."The deadly confrontation between George Zimmerman and Trayvon Martin is a horrific reminder of the toxic mix of an armed citizenry and a society that still makes too many judgments filtered through racial stereotypes."