BOSTON — The Massachusetts Appeals Court has granted a new trial to a man convicted of second-degree murder in the 2007 shooting of an off-duty Revere police officer.

During his trial, prosecutors said Robert Iacoviello (YAC’-oh-vee-ELL’-oh) fatally shot Officer Daniel Talbot in a field behind Revere High School after Talbot and one of Iacoviello’s friends were involved in an argument.

Talbot and some other off-duty officers had been drinking and socializing.

Iacoviello’s lawyers argued that the trial judge made a mistake by not giving the jury instructions on self-defense or manslaughter.

Jake Wark, a spokesman for the Suffolk District Attorney’s office, says prosecutors are expected to appeal Thursday’s ruling to the state’s highest court. He says prosecutors will argue that there was no evidence the defendant acted in self-defense or that Talbot was hit by an errant shot.