Inside the Holcom Recreation Center Friday night, people were exercising in one form or another. Outside, a thief was breaking into cars at random.

Between 9:30 p.m. and 10 p.m. Friday, someone broke into five cars, shattering the front passenger windows and rummaging through the belongings inside. Several of the cars had alarms, but none was triggered, said David Pellet, whose alarm-equipped 1993 Isuzu Trooper was among those vandalized.

Police told the victims that the burglar could have used a device called a “punch-it,” which can puncture glass with swift, focused force that won’t set off car alarms.

The wallet of Pellet’s wife, Mary, turned up missing. The burglar also took out a children’s backpack, rummaged through it, and left it in the unlit, tree-covered area behind the parking lot with its contents strewn about the grass next to the ball diamond. The burglar apparently didn’t take anything from the backpack, Mary Pellet said.

Police told the victims that cars parked in the lot at 2700 W. 27th St. had been similarly targeted as many as four times in the past year, said Robin Willis, Lawrence, one of Friday’s victims.

A spokesman for the Lawrence Police Department said he was unable to verify similar break-ins at Holcom.

Willis was leaving a city league volleyball game when she found remnants of her passenger window sprinkled about the ground and interior of her car. Her children’s backpacks also had been rummaged through, but she didn’t think the burglar had taken anything from them.

Willis had locked her car and left her purse in it, but the burglar didn’t find it.

“It was too cluttered,” she said with a weary chuckle.

At least one other wallet was taken from another car.

Police did not have damage estimates or theft totals Friday night.

The cars were parked about 30 yards from the entrance to the building. About 15 cars were in the parking lot when it became known that some had been forcibly entered, Willis said.