When a killer falls through FBI’s net

Omar Mateen was taken off a terrorist watch list after a long and intensive investigation. Then he killed 49 people. It’s the third recent time — including the Boston bombing — that someone who came under scrutiny by the FBI carried out an attack later.

The gunman who carried out the deadliest mass shooting in U.S. history had twice come to the attention of federal law enforcement authorities. He was placed on a terrorist watch list, investigated, interrogated and determined not to be a threat.

That assessment proved horribly and tragically wrong. But that obvious-in-hindsight assessment is only the beginning of a conversation, not the conclusion, and certainly not an indictment.

The FBI has said it will conduct a review of its past investigations into Omar Mateen to determine if mistakes were made or signs missed that could have prevented Sunday’s rampage at an Orlando, Fla., nightclub, in which 49 people were murdered and an additional 53 wounded. The 29-year-old gunman, an American-born citizen born to Afghan parents, had been placed on a terrorist watch list for nearly a year after co-workers alerted authorities in 2013 to inflammatory comments he made. He was taken off the list after an intensive investigation, including use of an undercover informant, concluded that he had broken no laws and that his talk of ties to terrorists was mere bluster. His name surfaced months later in a separate probe, but agents again concluded no action was warranted.

Posing the question of whether things should have been done differently, FBI Director James Comey said, “So far, I think the honest answer is: I don’t think so.” If in fact procedures were followed and no obvious clues missed, the questions become more difficult. Are the procedures adequate? Were allegations of domestic abuse known and factored in, and should they have been? Can better predictive methodologies be developed?

We ask these questions with appreciation of the difficulty of the job. Comey characterized the challenge of detecting lone-wolf terrorists as not only looking for “needles in a nationwide haystack” but also figuring out “which pieces of hay might someday become needles.” As President Barack Obama said Tuesday, “We work to succeed 100 percent of the time. An attacker, as we saw in Orlando, only has to succeed once.”

Moreover, on alternate weeks, the FBI finds itself criticized for being too intrusive, overusing sting operations that defense lawyers characterize as entrapment and maintaining long watch lists of people who have been convicted of no crime. Americans expect law enforcement to protect them from danger — while also respecting their privacy and their right to dissent.

Nonetheless, this is the third time in recent years that someone who came under FBI scrutiny, including the Boston Marathon bombers, ended up carrying out a later attack. Are there lessons to be learned from how someone known to authorities went on to kill? We should not expect perfection, but we should expect the FBI to be rigorous in its review of this case — and as transparent as possible about the lessons that it draws.

— THE WASHINGTON POST