In the quiet early morning hours in Sun City, Arizona, a violent encounter shattered the peace and ended the lives of two women. Marcia McGrath, a 53-year-old female, and her 77-year-old mother, Thea Merlino, were attacked in their home on June 25, 2024. Responding to a 3:07 a.m. emergency call about a man with a gun, Maricopa County Sheriff's Office deputies arrived at a residence on Newcastle Drive to a harrowing scene.
Upon their arrival, deputies heard cries for help coming from inside the apartment. The door appeared to have been forced open, and inside they discovered both women suffering from gunshot wounds. Thea Merlino was found deceased at the scene, while Marcia McGrath was severely injured. Despite the life-saving efforts of the deputies and subsequent transport to a hospital, Marcia succumbed to her injuries and was pronounced dead shortly after her arrival. Before she passed away, however, she was able to identify her attacker to the deputies providing her with medical aid. She stated that her ex-husband, Robert McGrath, was the person who had shot her. She also provided details that he lived in El Mirage and a description of his truck. Just a week prior to the tragic event, on June 17, Marcia had filed for divorce from Robert McGrath.
The investigation swiftly focused on 60-year-old Robert Alan McGrath. He was located and arrested later the same day at his home in El Mirage. Neighbors in Sun City had also encountered Robert McGrath that morning. One neighbor, after hearing a loud noise from the apartment, went to check on the residents and was confronted by a man with a handgun, later identified as Robert McGrath. He threatened the neighbors, ordered them to the ground, and stole a cellphone before they were able to escape and call for help. It was also revealed that weeks before the murders, Marcia had reported to the El Mirage Police Department that Robert had threatened to kill her.
Robert McGrath was charged with two counts of first-degree premeditated murder, as well as kidnapping, armed robbery with a deadly weapon, first-degree burglary, and aggravated assault with a deadly weapon. In October, he pleaded guilty to two counts of first-degree premeditated murder and two counts of aggravated assault with a deadly weapon. On November 4, 2024, Robert McGrath received two life sentences for the murders of his wife and mother-in-law, along with an additional 15 years for the aggravated assault charges.
