The track record for the FBI in post-Sept. 11, 2001 terror cases is mixed, The Washington Post (NYSE:WPO) said Monday.

There have been no new attacks on U.S. soil, but also few stunning victories in court against homegrown terrorist "sleeper cells," the newspaper said. And there have been some high-profile acquittals or hung juries in terror investigations.

Robert Chesney, who studies federal terrorism cases at Wake Forest University, says that dims the notions of success.

"The bottom line is that they are doing considerably better than is often reported ... but they certainly aren't doing perfectly and they've had plenty of black eyes along the way," Chesney said.