A former Minneapolis parks police chief was sentenced Monday to 18 years in prison for molesting a teenage boy who was a family friend.

William Allan Jacobs, 68, of Lutsen pleaded guilty in March to three counts of second-degree criminal sexual conduct and three counts of possessing child pornography, the Minneapolis Star Tribune reported.

The victim, who was 15 at the time, told police in January 2010 Jacobs had molested him on camping trips and at the man's house and cabin during a three-year period.

Authorities said Jacobs, who also had worked as a teacher, camp counselor and coach, may have molested dozens of boys over three decades, though the statute of limitations precludes prosecuting him, the newspaper said.