West Valley man behind bars after allegedly killing wife and her mother

Jun 26, 2024, 2:12 PM

Mugshot of Robert McGrath, who is accused of killing his wife and her mother in a Sun City double-h...

Robert McGrath is accused of killing his wife and her mother in a Sun City double-homicide case. (Maricopa County Sheriff’s Office Photo)

(Maricopa County Sheriff’s Office Photo)

PHOENIX – A West Valley man is behind bars after allegedly killing his wife and mother-in-law on Tuesday, according to authorities.

Robert McGrath, 60, was arrested at his El Mirage home after double-homicide in Sun City, according to court documents.

He was booked into jail on multiple felony charges, including two counts each of first-degree murder and kidnapping. His cash-only bond was set at $2 million.

McGrath is accused of killing 53-year-old Marcia McGrath and her mother, 77-year-old Thea Merlino, at an apartment complex near 111th Avenue and US 60/Grand Avenue.

Marcia McGrath had filed for divorce on June 17. A few weeks earlier, she told El Mirage police that her husband had threatened to kill her, according to the probable cause statement for Robert McGrath’s arrest.

What do we know about deadly West Valley incident?

Deputies responded to the Sun City double-homicide scene after receiving an emergency call just after 3 a.m., according to a Maricopa County Sheriff’s Office press release.

The callers had gone to check on a neighbor’s apartment after hearing a loud noise. They encountered an armed man later identified as McGrath at the doorway.

MCSO said the suspect ordered the callers to the ground and pointed a gun at them before he went back into the apartment. The callers then fled back to their home and alerted MCSO.

What did deputies find at Sun City double-homicide scene?

When deputies arrived, they heard woman calling for help from inside the apartment where the suspect had been seen earlier.

They found two gunshot victims inside. Merlino was pronounced dead at the scene, and Marcia McGrath died shortly after being taken to a hospital. However, she was able to tell deputies that her husband was the shooter, according to court documents.

Deputies found Robert McGrath at his El Mirage residence along with ammunition that was the same caliber as casings found at the shooting scene, according to the arrest report.

“Our thoughts continue to be with the victims’ family members. I would like to commend the brave actions of the community members for their observations and courage in swiftly reporting this tragic incident,” Sheriff Russ Skinner said in a press release Wednesday.

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West Valley man behind bars after allegedly killing wife and her mother