Gallegos-Mendoza was the man behind the wheel as 28-year-old José Adrián Rodríguez-Ramírez fired the shots at the victim.
José Raul Rubio-Navarro, the brother of the victim, said through a translator during the sentencing hearing, "I just want justice to be done for what they did on that day." He added that his family felt they were being mocked and wanted those responsible to be punished.
Deputy Salt Lake County District Attorney Yelena Ayrapetova called the events of that day "nothing short of an assassination-style drive-by shooting." She said Gallegos-Mendoza wasn't remorseful, and that he and the shooter were wearing matching hoodies and threw the gun in the river.
Defense attorney Clayton Simms said his client has no previous criminal history and wasn't affiliated with any gangs.
Gallegos-Mendoza said through a translator that he feels "miserable" and "broken" for what he did.
"I was there, but not with that intention," Gallegos-Mendoza told Judge Elizabeth Hruby-Mills. "There is not a single day I wish it didn't happen. I wish I hadn't driven the car."
The shooter, Rodríguez-Ramírez, pleaded guilty to first-degree felony murder and is serving 15 years to life in prison.
Following the shooting, police learned Rodríguez-Ramírez was having an affair with the victim's common-law wife, 24-year-old Maria Marta Campusano.
Rodríguez-Ramírez told police he feared for his safety because Campusano's husband had learned of the affair. He also said he learned from Campusano that Rubio-Navarro was a heavy drinker and abusive toward her.
Initially, Gallegos-Mendoza and Rodríguez-Ramírez had each pointed to the other as being the shooter.
Campusano was acquitted last year at trial of obstructing justice for allegedly lying to police about her relationship with Rodríguez-Ramírez. She has since been deported, according to prosecutors.
After the driver's prison sentence is up, he will be deported.
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