BALTIMORE (AP) — Six people were fatally shot in Baltimore in a single night, prompting local police to deploy additional officers to the streets on mandatory 12-hour shifts to try and quell the bloodshed.

Baltimore Police Commissioner Kevin Davis described Monday night’s rash of killings as “an unconscionable amount of violence in a short amount of time.”

(Screengrab from news briefing via Facebook)

Davis said between 8:20 p.m. and 3:25 a.m. on Tuesday, officers responded to five separate incidents, including a quadruple shooting that killed two people and left two others injured. The rest of the incidents were fatal shootings.

“It’s guns, gangs and drugs,” Davis said at a news conference on Tuesday, adding that all of the victims were known to law enforcement.

“I expect people to be upset, to want a better Baltimore, to want a sense of peace and tranquility when they go to their car or to work or walk in the neighborhood, that they don’t have to put up with this crap,” Davis said. “We’re fighting our way through this. There’s nowhere for us to run, nowhere for us to hide. We’re responsible for public safety in the city of Baltimore and we’ll continue working our hearts out.”

Davis said he spoke on Tuesday morning with members of the Federal Bureau of Investigation, the Drug Enforcement Administration, the Bureau of Alcohol, Tobacco, Firearms and Explosives and local law enforcement partners to address the violence. Davis said that effective immediately, every officer in the department who is able to be deployed on street duty will be.

So far this year the city has seen 159 homicides, include 38 killings in May and 32 in January. The murder rate began to skyrocket in Baltimore in 2015, following the April death of Freddie Gray, a young black man whose neck was broken in police custody. Gray’s death inspired civil unrest, prompted criminal charges against the six officers involved, and precipitated the firing of then-police commissioner Anthony Batts. Since then, the violence in this city has not relented.

Davis said Tuesday that criminals in Baltimore don’t fear the justice system because it doesn’t function as it should, particularly when it comes to keeping those convicted of gun and violent crimes behind bars.

“They don’t fear an arrest, they don’t fear a successful prosecution, and they don’t fear a guilty verdict,” he said.