Man Accused Of Murdering His Ex's New Fiancé, Who Was A 'Loved' High School Teacher

A San Diego man has been accused of fatally shooting his ex-girlfriend’s new fiancé, a beloved high school teacher described as “vibrant and full of life,” in a street attack this week.

When Mario Fierro, 37, was shot dead on a sidewalk Monday morning, police were initially at a loss for suspects. Witnesses gave inconsistent details about the shooter and his vehicle, and they were told that as a teacher at Cathedral Catholic High School, Fierro was almost well-liked, CBS8 reports.

But investigators soon zeroed in on a person of interest: Jesse Alvarez, 30, who is the ex-boyfriend of Fierro’s new fiancé.

Fierro’s fiancé, who has not been named, had ended her three-and-a-half-year relationship with Alvarez in September 2019 — and a few months later, she filed for a restraining order, local station KNSD reports.

The woman claimed Alvarez had shown a pattern of increasing control and manipulation while they were dating, and he’d only become more aggressive following their breakup, according to documents acquired by the station. On one occasion, the woman claimed he tried to break into her home using a copy of her house key. Another time, he allegedly followed her and her sister around a theme park, repeatedly asking to speak with her in private.

“I need this protective order for my safety and security… I am extremely afraid he will harm me,” she wrote in her application for a restraining order.

Her request for a restraining order was initially granted, but at a hearing in January 2020, Alvarez vehemently denied all of her claims. Unable to determine which of the two was telling the truth, the judge rejected her application, according to KNSD.

Prior to Monday's shooting, witnesses had seen Fierro getting into an argument with another man, a police spokesperson told CBS8. Fierro and Alvarez’s ex had become engaged just a few weeks prior.

Alvarez was arrested Monday night and charged with first-degree murder, according to online inmate records.

Meanwhile, Fierro’s death has left his community reeling.

“Everyone in our school community mourns his loss. Mario was young, vibrant and full of life. All of us loved him,” Kevin Eckery, a school spokesperson, told CBS8.

A vigil was held in Fierro’s honor Monday night, and a neighborhood fund has been set up to help pay for his funeral. That fund had raised almost $50,000 as of Wednesday afternoon.

Fierro is remembered as both a teacher and a special teams football coach who inspired countless young men.

“He just always believed in me. Not many other people did when I was told I might never be able to play football again,” Keenan Guthrie, a Cathedral Catholic student, told CBS8 through tears.

Alvarez is being held without bail, according to online records. It’s not clear if he has an attorney who can comment on his behalf.