Police have arrested two people for an alleged prostitution ring they said involved a 16-year-old girl.

The Janesville Police Department said detectives received a tip Tuesday that prostitution was going on at a Center Avenue address, and a day later the mother of a 16-year-old girl from Walworth County reported that her daughter had been forced to have sex for money at a Janesville house.

They arrested Patrick Cooper, 27 and Erica White, 28, at the home Thursday.

On Thursday, police executed a search warrant at a house on Center Avenue and found evidence that corroborated the tip, including condoms and drugs.

According to the search warrant, the tip alleged that  Cooper was acting as a pimp for White, 28 and the 16-year-old.  Police interviewed the girl, who had run away from home, who said that Cooper would post ads on Backpage.com for sex and they would meet men at the Community Action Daycare parking lot down the road and walk back to the home.  Police said those customers came from around south-central Wisconsin and northern Illinois.

"It is absolutely concerning that people came from other areas to this location," said Janesville Detective Erik Goth.  "It does make you wonder if there's a belief that because this is not as common in Janesville that it is a better location for an operation like this."

The girl allegedly told police she met the couple at a party.

"She explained that she needed a place to stay so under the guise of a gesture of goodwill she stayed with them and then the events turned out the way they did," said Goth.

Cooper also owned a gun, which he kept in a toolbox near a bedroom door, according to the warrant.

Cooper and White were charged with sexual exploitation of a child, police said.

A downstairs neighbor of the couple said she was shocked at the allegations, but that suspicious activity had been increasing.

"One time I heard someone outside my window coughing and it was a truck driver and I said 'What are you doing? Get off my front porch,' and he said "I'm here to see my cousin," and I'm like 'Yeah, right,'" said Vonda Vogel.

Police said the investigation was ongoing and it wasn't clear Friday morning if more people would be charged in connection with the case.