Maine State Police are mourning the loss of police dog Preacher, a 4-year-old Belgian Malinois killed in the line of duty during a tactical operation Monday evening. Preacher and his handler, Sgt. Jonathan Russell,

Preacher and his handler, Sgt. Jonathan Russell, were deployed to a domestic dispute that led to an armed standoff involving 29-year-old Steven Righini, who shot an Aroostook deputy, according to a statement from MSP.