AUBURN – A former part-time Mechanic Falls police officer has pleaded guilty to one count of operating under the influence, and paid a $600 fine. His license has been suspended for 90 days.

Robert E. Wallingford III, 34, formerly of Lisbon, entered the plea in Androscoggin County Superior Court where he was scheduled for trial later this month, facing a single charge of criminal OUI, a Class D misdemeanor, punishable by up to a year in jail.

Wallingford, who now lives in Westbrook, was stopped on Jan. 1 a little after 8 p.m. on Ferry Road in Lisbon and given a field sobriety test. A blood-alcohol test later showed Wallingford had a level of .15 percent or more, according to superior court records.

Wallingford waived arraignment and pleaded not guilty through his attorney, Leonard Sharon, and had requested a jury trial before reaching this plea deal.

Wallingford was put on administrative leave then resigned about a week after the incident, Mechanic Falls Town Manager John Hawley said. As a reserve officer, Wallingford was not salaried and worked for hourly pay.