CHICAGO (CBS) — A string of mass shootings Sunday morning helped contribute to the bloodiest weekend of the year in Chicago, leaving at least 12 people killed and 54 others wounded in shootings since Friday evening.

Police said there were a total of 33 shooting incidents from 6 p.m. Friday through midnight Sunday night, with 66 total victims, including 12 murders. Fourteen of the shooting victims were juveniles, including two who died.

Authorities said dozens were shot in six mass shootings during a seven-hour span early Sunday, with at least four people shot in each of those attacks. Those six shootings alone left a combined three people dead and 28 others wounded.

The pain of dozens of families echoed through the parking lot of Stroger Hospital on Sunday, as more than a dozen gunshot victims were treated there after the spate of mass shootings; some needing comfort and help to stay upright, others so stricken by grief they could no longer stand.

Police said from 10 a.m. Saturday until 10 a.m. Sunday, at least 34 people were shot, five of them fatally.

In a hastily called news conference Sunday night, after reporters sought answers about the weekend’s bloodshed, Chicago Police Department said many of the incidents were the result of gang conflicts.

Chief of Patrol Fred Waller blamed gang members who often target one specific person in a group, but end up wounding several innocent bystanders.

“When it’s very hot outside, we have multiple areas with crowds. … An offender, or some type of rival gang sees a large group of people,” he said. “They take advantage of that opportunity, and they shoot into a crowd, no matter who they hit.”

Waller said, despite the recent violence, shootings are down 30 percent this year compared to 2017.

“We won’t be defeated. We won’t be overrun by that small group, that small element that’s committing these reckless acts. We will not. I promise you that we will not be defeated,” he said.

The gunfire continued Sunday night into Monday morning.

Police said a group of people was standing in front of a home near 27th and Dearborn in the Bronzeville neighborhood shortly before 8 p.m., when a man jumped out of a car, fired several shots, and hopped back in the vehicle. When the dust settled, three people had been shot, including a 24-year-old man who was killed.

About four hours later, another man was killed early Monday morning, when a person wearing a ski mask walked up to a man and a woman standing in front of a home near 130th and Drexel, and shot them both. A 50-year-old man was shot in the head, and was pronounced dead at the scene. A 55-year-old woman was shot in the leg, and was stabilized at Advocate Christ Medical Center in Oak Lawn.

Police Supt. Eddie Johnson planned to hold an 11 a.m. news conference on Monday to discuss the weekend’s violent crime.

The spate of shootings this weekend started only a day after a group of about 150 anti-violence activists briefly shut down Lake Shore Drive on Thursday with a protest march to Wrigley Field.

Less than a month ago, Rev. Michael Pfleger led thousands of protesters in a march that shut down the Dan Ryan Expressway, calling for an end to gun violence in Chicago.

“It’s absolutely outrageous. It’s a state of emergency in our city,” Pfleger said Sunday in response to the series of mass shootings earlier in the day. “Someplace else in the country, the whole country would be talking about that this morning. All world news and national news would be talking about that. Four types of mass shootings going on in Chicago with those numbers, and it’s a weekend in Chicago, a rough week
end. No it’s not a rough weekend! It’s absolutely ridiculous. It’s unacceptable.”