Sometimes there may be no good alternatives

Documents Unsealed in Anthrax Case - NYTimes.com via kwout

Robert M. Blitzer, who formerly directed the F.B.I.’s section on domestic terrorism, bristled at criticism of the bureau’s methods in the anthrax case and called them a necessary part of tracking down the killer.

“You do the best you can, and it’s not always pretty,” he said. “A lot of times you interview folks over and over again, and you know they’re lying and you’ve got to figure out why. It’s a tough business. Here, you have a bunch of people dead and several diminished and you’re charged with solving the crime. You try not to step on peoples’ toes, but sometimes it happens.”