PORTLAND, Maine (AP) A man charged in the shooting death of his wife in Maine told a 911 operator that he thought she was an intruder and followed instructions for performing CPR.

Noah Gaston became emotional Monday, burying his head in his hands, as jurors heard the 911 recording of his failed resuscitation attempts.

Thirty-four-year-old Alicia Gaston died from a shotgun blast in the stairwell of the family’s home in Windham on Jan. 14, 2016. Prosecutors say Gaston intended to kill his wife while the defense told jurors it was a tragic accident.

Gaston is on trial on murder and manslaughter charges.

Their three children were home at the time of the shooting. Their 8- and 9-year-old daughters told police they heard arguing before the shot was fired.