Inset: Roberto Antonio Trejo (Arizona Department of Corrections). Background: Number 1 Buffet in Avondale, Ariz., where Trejo killed a 66-year-old man in the parking lot (Google Maps).

A 22-year-old Arizona man will spend two decades behind bars for killing a man who was set to retire from his job and move to a new state, authorities say.

Roberto Antonio Trejo was sentenced to 20 years in prison for the shooting death of 66-year-old Frank Vitale, the Maricopa County Attorney's Office said. Trejo pleaded guilty in April to second-degree murder.

The shooting occurred shortly after noon on Oct. 14, 2024, in Avondale, just outside Phoenix.

Vitale had just finished lunch at Number 1 Buffet. As he sat in his car in the parking lot, Trejo walked up to him.

"Without warning, Trejo pointed a handgun through the window and shot Vitale before fleeing the area," prosecutors wrote.

Trejo and Vitale did not know each other and there was no apparent motive for the shooting.

Local CBS affiliate KPHO reported at the time that after the shooting, surveillance video showed a suspicious man running away and looking over his shoulder. Cops took Trejo into custody about 45 minutes after the shooting. He had a handgun on him.

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Trejo had just been released from prison five months earlier after an aggravated assault conviction and was on probation at the time of the shooting.

Prosecutors said Vitale had just bought a home in Arizona where he was going to live with his sister after he retired from his job. Vitale lived on Long Island, New York, and worked at Home Depot, according to his obituary.

"No amount of time will be enough to make up for the pain and suffering this defendant has caused," County Attorney Rachel Mitchell said in a statement. "At 20 years old, he had the opportunity to improve his behavior but instead chose to do the unimaginable and take a life. Thanks to the work of homicide prosecutor Daniel Strange, this defendant will no longer be a threat to the community."