Photo: AP

During a press conference Friday, Dallas Police Chief David O. Brown revealed that the fourth suspect in the Dallas attack died not by a self-inflicted gunshot wound, as had previously been reported, but by a bomb detonated by police officers. It appears to be the first time law enforcement has used such a tactic on U.S. soil.

Police tracked the man, who has been identified as 25-year-old Micah Johnson, to a parking garage in downtown Dallas at the El Centro community college campus. The confrontation, which reportedly involved the exchange of gunfire, lasted “several hours” into the early morning.

Though details are still scant, Chief Brown said at a press conference Friday morning that police killed Johnson with a robot bomb early Friday morning after he refused to surrender.

“Negotiations broke down. We had an exchange of gunfire with the suspect. We saw no other option but to use our bomb robot and place a device for it to detonate where the suspect was,” Brown said. “Other options would have exposed our officers to great danger. The suspect deceased as a result of detonating the bomb. The reporting that the suspect killed himself is not accurate. We confirmed that he’s been deceased because of the detonation of the bomb.”

Police routinely employ robots in confrontations with suspects, usually to disable explosives, but this case appears to be the first where officers deliberately used one to kill a suspect. (Chris Dorner, who allegedly killed at least four people during a rampage in 2013, was trapped in a burning cabin after police used robots to launch smoke bombs inside; their intent did not appear to be to kill him via robot.)

It’s unclear if the Dallas police has ever considered such a method before, or what their guidelines for killing a suspect with a robot entail. A voicemail and email left with the Dallas Police media relations unit had not, at press time, been returned.