(Newser) – As Dzhokhar Tsarnaev hid on a boat in Watertown, law enforcement let bullets fly—but the suspect himself didn't have a gun, officials tell the Washington Post. During the half-hour before his capture, police were engulfed in "the fog of war," says one law-enforcement source; some cited desperation to catch Tsarnaev for questioning as the reason for the gunfire, but the FBI has thus far refused to comment on what sparked it, or whether any of those bullets struck Tsarnaev.

Officials likely didn't know whether Tsarnaev was armed, says an official. "Hours earlier, he and his brother had killed a police officer, shot another officer, and thrown explosives out of their cars as the police were chasing them. They couldn’t assume that he did not have a gun and more explosives." Adds a colleague: "You can’t second-guess what they were doing on that scene ... Their own lives were in danger." An FBI spokesman referred to a "tremendously effective outcome under dire circumstances." (Read more Dzhokhar Tsarnaev stories.)

