BAKERSFIELD, Calif. -- Community parks and bike trails are places where people can go and have fun, but a call to the Eyewitness News tip line uncovered a different type of recreation that has been occurring in those places.

The caller said men go to parks to have sex with other people.

"People have a hidden lifestyle that they don't show to other people," said the anonymous witness, who said he's seen the lewd acts take place at Bakersfield parks.

"They go there, they sit in their cars, they walk around the park," said the witness. "You go to use the restroom at the park, and there will be people there together in the bathroom."

The acts are either between a man and woman or two men. As a gay person, our witness said he's upset by this activity, because it creates a negative stereotype of the gay, lesbian, bisexual and trans-gender community.

"This isn't your normal everyday, out, gay person that you work with or friend or family member," he said. "This is somebody that's got a secret they're hiding from people."

While it may be a secret, our witness said the men are not shy about asking for sex.

"I've had people come up to me and pull out their private parts and flash them right to you right there and say, 'Is this what you want?'" he said.

Eyewitness News decided to use an undercover camera to see for if the sexual activity was really happening. Investigators went to several parks throughout Bakersfield.

In one instance, Eyewitness News investigators placed a hidden camera on a man at Yokuts Park. After sitting outside for about 10 minutes, the decoy was approached by a man. The conversation was innocent at first, but the man suggested they go somewhere more private to talk. Once they got to a nearby bike trail, the man started asking for sexual favors.

Evidence of sexual acts is easy to find. Eyewitness News found dozens of condom wrappers, used condoms and other sexual paraphernalia.

Eyewitness News took the video evidence to Bakersfield police and asked Det. Mary DeGeare if what's happening at the park and off the bike trails is illegal.

"The law prohibits a person from soliciting another person to participate in lewd conduct while in a public place," she explained. "From what I'm seeing on the video, the elements are present."

When asked if police could crack down on this activity, she said they need the public's help.

"If anyone is aware that this is taking place then they need to report it, and we will respond to it," she said.

The secret witness said stricter enforcement could make the parks a little safer.

"I see families out there at the barbecue area, (and) any little kid can walk into the bathroom," the witness said. "It's dangerous, and no kid needs to see that."

Police have made four arrests this year for sexual solicitation in public places.