ALFRED, Maine — A former Biddeford landlord who admitted to killing two of his tenants was sentenced to life in prison Thursday.

Earlier this month, 77-year-old James Pak pleaded guilty to two counts of murder.

Pak shot and killed 19-year-old Derrick Thompson and 18-year-old Alivia Welch in December 2012.

He also shot Thompson’s mother, Susan Johnson. She survived.

According to police, Pak shot the teens because of a dispute over parking.

For three years, Pak pleaded not guilty by reason of insanity, but he changed his mind Feb. 2.

Pak was sentenced Thursday afternoon at York County Superior Court in Alfred. He will spend the rest of his life in prison.