The Guardian Angels are among the authorities patrolling the North Avenue Beach area Wednesday night following several bouts of violence earlier this week.
In the most severe, a teenager who witnesses said was flashing gang signs was shot Monday night and remains in critical condition.
Earlier that evening, police say six 15-year-olds, including four boys and two girls, attacked an 18-year-old Barrington girl and hit her in the face at about 8 p.m. Monday.
Charges against the teens ranged from resisting a police officer to aggravated battery to a police officer.
"It was probably gang-related because this year it seems like more gangs are coming out," said Rocco Nedas, who has worked at the beach for two summers and says the beach could have its own reality show.
Two hours later and just steps away in the tunnel that connects the lakefront trail with Inner Lake Shore drive, words turned to violence between two bikers and a group of pedestrians as the bikers were trying to pass. There were no serious injuries, but two more teens were arrested and charged with assault and battery.
One beach goer said she couldn't believe how many people were openly flashing gang signs and starting fights until police arrived in heavy numbers.
"There were probably 50 squad cars, no exaggeration, 100 police officers or so, undercover [and] regular police officers. The beach was full with about 1,000 people and it wasn't your typical Monday night, lakefront young professionals," said Katie Ryan.
Chicago Mayor Richard Daley downplayed the incidents during remarks Wednesday.
"They're isolated incidences. We look at it. We look at it very carefully. We make sure we have better lighting, we make sure we have access there, we make sure the beach patrol is out there as early as possible."
Police were out Wednesday morning searching coolers for alcohol. It's not allowed on park district property and Beach House employees say it's the root cause of much of the violence.
"I've seen people pass out a lot. Police are always coming here, ambulances coming here taking people away," Nedas said.
we typically beef up the police presence along the lakefront around Memorial Day, something that is expected with warmer temperatures and increased traffic there. This year will be no exception," said Chicago police Lt. Maureen Biggane.