Police said an Oregon man, responding to a fake online ad, unknowingly spoke over speakerphone to an entire class of officers training on human trafficking investigations to set up a “tryst,” then was cited in front of the West Linn police station, where officers set up their meeting.

The West Linn Police Department hosted training for human trafficking investigations Tuesday. As part of the program, the investigators teaching the class placed an ad on escort websites, the department said.

Throughout the class, a phone with a number listed in the ad continuously rang with would-be customers trying to contact the fictitious West Linn 19-year-old the investigators created and listed in the ad.

The West Linn police said one caller, Rene Cruz Mesa, of Woodburn, Ore., agreed while on speakerphone to meet the woman. He told the officer on the other end he was working in West Linn as a landscaper and asked where to go.

The investigator posing as the 19-year-old gave Cruz Mesa the address to the West Linn Police Department, and — to the bewilderment of those in attendance, the department said — Cruz Mesa drove to the police department, all while continuing to speak with the investigator. He even described his truck.