A onetime Minneapolis police officer was convicted Wednesday of sexually abusing his son’s 16-year-old girlfriend over a period of months, in hotel rooms and during ride-alongs in his police cruiser.

David E. Campbell, 60, was found guilty in a bench trial by Hennepin County District Judge Tamara Garcia of three counts of criminal sexual conduct in the third-degree, two counts of fourth-degree criminal sexual conduct, one count of terroristic threats and one count of stalking.

The longtime patrol officer, who was put on leave after the allegations surfaced and later retired, will be sentenced on Dec. 3. Lawyers on both sides will be arguing for a term ranging from three years to 4¾ years. The County Attorney’s Office said it intends to seek the lengthier sentence.

Prosecutors alleged that Campbell had molested the teenager, who had been staying with his family while they lived out of hotels in Bloomington, Roseville and Minneapolis.

They said that details of the abuse were first relayed to the detective by a school social worker in St. Paul, who had spoken with the girl and her 17-year-old boyfriend, Campbell’s son.

She said Campbell had fondled her multiple times, often persisting even when she told him to stop, according to prosecutors. Several of the encounters reportedly happened during ride-alongs while Campbell was on-duty.

The victim told authorities that on one such occasion Campbell warned her not to report him, threatening to shoot her in the head if he got in trouble or had his kids taken away from him.