PONTIAC, Michigan — A 79-year-old former priest has pleaded guilty to sexually abusing teens more than 40 years ago when he worked at churches in suburban Detroit.

Gary Berthiaume entered pleas Monday in Oakland County Circuit Court to two counts of second-degree criminal sexual conduct, according to the Michigan Attorney General’s office.

Berthiaume also pleaded no-contest to one count of gross indecency.

Allegations against Berthiaume involved three juveniles who were between the ages of 13 and 15 in the 1970s when he served as a priest at St. Joseph Catholic Church in Wyandotte and later Our Lady of Sorrows in Farmington, the attorney general’s office said.

Berthiaume is scheduled to be sentenced Dec. 20.