"So far, the honest answer is I don't think so. I don't see anything in reviewing our work that our agents should have done differently. But we'll look at it in an open and honest way," Comey said this afternoon.
Richard Burr, Chairman of the Senate Intelligence Committee, agreed, saying "the dots don’t really connect to where there should have been a different action taken."
He detailed the three interviews the FBI had with Mateen. Two of them were in connection to "inflammatory and contradictory" statements Mateen made to co-workers while he was working as a security guard in a courthouse.
"Our investigation involved introducing confidential sources to him, recording conversations with him, following him, reviewing transactional records from his communications and searching all government holdings for any possible connections, any possible derogatory information. We then interviewed him twice," Comey said, noting that the investigation was then closed.
While Mateen was under investigation, he was placed on a terror watchlist, but he was taken off in March 2014 when the investigation was closed.
Comey said it is "not entirely clear at this point just what terrorist group he aspired to support," because Mateen gave differing indications when he spoke to a 911 dispatcher while inside the Pulse nightclub in Orlando.
Comey said that he would not be using the killer's name, in an effort not to glorify him.
"Part of what motivates sick people to do this kind of thing is some twisted notion of fame or glory. And I don't want to be part of that, for the sake of the victims and their families," Comey said.
"Our hearts are broken and ache," he said.
Comey responded to some additional questions after his televised remarks, though he was unable to answer all of them.
When asked why no flag was raised when the subject of an FBI terror investigation went to buy guns, Comey said that’s the “way the system is currently organized.”
He declined to answer whether such notifications should be made.
Comey said the FBI is now looking to see who may have “assisted in any way,” even if not part of a broader terror cell in the United States.
Deputy Attorney General Sally Yates spoke just before Comey, saying that it was "an attack on who we are as a nation."
"What happened in Orlando yesterday was a horrifying act, a horrifying act of evil and terror," Yates said.