Defendant Sentenced for First-Degree Murder of Ex-Girlfriend’s Fiancé

San Diego County District Attorney Summer Stephan announced today that Jesse M. Alvarez has been sentenced to life in prison without the possibility of parole plus an additional 25 years to life for killing Mario Fierro, the fiancé of his ex-girlfriend, in February 2021.

Last March, a jury found Alvarez, 34, guilty of first-degree murder, including the special circumstance of lying in wait.

“The defendant ambushed the victim and repeatedly shot him to death in a most cowardly and cruel manner,” DA Stephan said. “The victim, Mario Fierro, was a beloved teacher at Cathedral Catholic High School and his death left his school, family, fiancée and community grieving. I’m proud of the excellent investigation by the San Diego Police Department and the tireless work of the prosecution team led by Deputy DA Ramona McCarthy, who brought a measure of justice to this cold-blooded murderer.”

Defendant Alvarez prepared, planned, and executed the cold-blooded murder of a Cathedral Catholic High School teacher after he discovered he was engaged to Alvarez’s ex-girlfriend. On the morning of February 1, 2021, Alvarez arrived at the home of Fierro, ready to kill him. After waiting one hour for Fierro to come out of his home, Alvarez ambushed him, shooting him six times, four of which were at close range.

It’s not unusual for a new romantic partner to become a target of violence, as in this case and many others prosecuted in San Diego County. Domestic violence has many forms including physical aggression, sexual abuse, emotional or psychological abuse, stalking, or financial abuse.

The District Attorney’s Office not only prosecutes domestic violence offenders, but also works to prevent such crimes, providing resources to victims so they can safely leave their abusers and move on with their lives. If you or someone you know is being abused, call the National Domestic Violence Hotline at 1-800-799-7233. More resources can be found on the District Attorney’s website.

In addition, One Safe Place: The North County Family Justice Center provides support services all under one roof to anyone who has experienced child abuse, sexual assault, domestic violence, a hate crime, elder abuse, human trafficking, violent loss, family violence, or other abuse or victimization. OneSafePlaceNorth.org