Rob Fulton, former director of the St. Paul-Ramsey County Public Health Department, was arrested in a St. Paul prostitution sting Monday.

Fulton, 72, of Minneapolis, who retired from the department in 2010 after 22 years as its head, was part of a sting of six people who were arrested.

Investigators posted fake escort advertisements on controversial ad site Backpage.com, to which the suspects responded, said Sgt. Paul Paulos of the St. Paul police. Such sting operations are not uncommon, he said.

Fulton was arrested a little before 3 p.m. Monday for engaging in prostitution, a gross misdemeanor, according to a police report.

Before this incident, Fulton only had some speeding tickets on his record.

NICOLE NORFLEET