As protests against the acquittal of George Zimmerman continue in Los Angeles, Oakland and other cities, the NAACP is calling on the U.S. Department of Justice to file civil rights charges against Zimmerman for killing 17-year-old Trayvon Martin. On Monday, Attorney General Eric Holder described the killing of Martin as "tragic" and "unnecessary," but he did not indicate whether he intended to bring a federal case. "The reality is that it's not clear that Trayvon Martin had any peers on that jury," says NAACP President Benjamin Jealous. "And it does appear that there may have been a racial dynamic, and that some of the racial dynamics in the community -- which is a very racially divided community historically -- have come into play." Jealous also criticized the judge for inhibited discussion about racial profiling. "We went through this kind of surreal trial where the judge blocked all discussion of racism of racial profiling," Jealous says. Nearly one million people have signed an online NAACP petition asking for the DOJ to pursue a case.