An autopsy conducted Monday showed Sylville Smith was shot in his chest and arm, authorities said, backing up the official account of Saturday's shooting of a black man by a Milwaukee police officer.

But after two nights of violent protests, Mayor Tom Barrett on Monday announced a 10 p.m. weeknight curfew for teenagers to help curb the demonstrations.

Chunks of concrete and rocks hurled at police -- and shards of glass from shattered squad car windows -- injured seven officers, upping the two-day tally to 11 wounded cops, Police Chief Edward Flynn said on Monday.

Additionally, an 18-year-old man was shot and seriously injured, and officers had to use an armored vehicle to retrieve the man and take him to a hospital. Flynn said the city's ShotSpotter system recorded 30 instances of gunfire on Sunday night, after 48 instances were recorded on Saturday.

While the looting and burning of businesses that characterized Saturday night's melee was absent on Sunday, Flynn said three squad cars were damaged, a police BearCat vehicle was struck by two bullets, an automobile and several dumpsters were set ablaze and a store had its windows smashed.

"The individuals who are doing this are making it more difficult -- not less difficult -- to attract investments and jobs in the very neighborhoods where we need them the most," Barrett said.

Police arrested 14 people on Sunday, all adults and all for disorderly conduct.

“I won’t be happy until these creep rioters crawl back in their hole,” Milwaukee County Sheriff David Clarke said on “America’s Newsroom” on Monday.

Wisconsin Gov. Scott Walker put the National Guard on standby for any repeat of violence. Protests were peaceful most of Sunday evening before a confrontation between police and demonstrators after 11 p.m. The Guard was never called in.

Flynn said Sunday that Smith was shot after he turned toward an officer with a gun in his hand.

Flynn cautioned that the shooting was still under investigation, but that based on the silent video from the unidentified officer's body camera, the officer "certainly appeared to be within lawful bounds."

At the same news conference, Barrett said a still image pulled from the footage clearly showed a gun in Smith's hand as he fled a traffic stop Saturday.

"I want our community to know that," Barrett said. But he also called for understanding for Smith's family.

"A young man lost his life yesterday afternoon," the mayor said. "And no matter what the circumstances are, his family has to be hurting."

Flynn declined to identify the officer who shot Smith but said he is black. Flynn said he wasn't sure what prompted the stop but described Smith's car as "behaving suspiciously."

After watching the officer's body camera footage, Flynn said the entire episode took about 25 seconds, from the start of the traffic stop until shots were fired. He said Smith ran "a few dozen feet" and turned toward the officer while holding a gun.

"It was in his hand. He was raising up with it," the chief said. He said the officer had told Smith to drop the gun and he did not do so.

The Associated Press contributed to this report.