SALEM, Mass. (AP) A former youth minister who previously served in Maine churches has pleaded guilty to sexually assaulting three vulnerable boys that he met through church, prosecutors said.

Russell Davis, 70, of Seabrook, New Hampshire, and formerly of Newbury, Massachusetts, was sentenced in Salem Superior Court on Wednesday to up to four years in state prison after pleading guilty to multiple charges, including child rape, according to a statement from Essex District Attorney Paul Tucker.

The victims ranged in age from 12 to 16 and the assaults occurred in Massachusetts between 1988 and 2006, prosecutors said.

Davis, a 20-year postal service employee, befriended and offered to mentor the victims he met through the United Methodist Church, prosecutors said.

The boys “came from homes lacking a complete family unit and, in some cases, sought assistance from the church to provide structure in their lives,” the district attorney’s office said.

Davis served in churches in Massachusetts, New Hampshire and Maine, according to the United Methodist Church New England Conference.

“Our pastors hold a position of authority and trust, and when that trust is violated, harm is done,” the conference said in a statement. “We share the grief and sense of betrayal experienced by the victims and those close to them.”