Walworth County prosecutors on Thursday charged another man with trying to pay for sex with a person he believed was a 15-year-old girl after a police sting operation in Whitewater.

Victor M. Armas Calvillo, 41, of 553 N. Chatham St., Janesville, was charged with using a computer to facilitate a child sex crime and trafficking of a child after police took him into custody Nov. 2, according to the criminal complaint.

The trafficking of a child charge alleges Armas Calvillo “did knowingly attempt to solicit a child for the purpose of (a) commercial sex act.”

Last week, the district attorney’s office filed the same charges after a similar sting against Allen J. Sorenson, 31, of 53½ N. Janesville St., Milton.

A few Walworth County police agencies were part of the sting. They made sex solicitation ads for a 14- or 15-year-old girl and posted them online, the complaint states.

When people responded to the ad, police set up meetings in Whitewater.

Armas Calvillo on Nov. 1 responded to the ad and asked, “You want to do business?” and at what price, according to the complaint. A detective told him it would be $120 for an hour.

After the detective sent Armas Calvillo a photo of a 15-year-old girl, the Janesville man responded, “I think you are a very pretty girl,” according to the complaint.

The next morning at about 7:54 a.m., Armas Calvillo reached out again, and a female officer spoke to him over the phone and set up the meeting, the complaint states.

Armas Calvillo had money, condoms and his Mexican ID card when he was taken into custody, according to the complaint.

He is next scheduled to appear in court at 2 p.m. Dec. 17 for a preliminary hearing.