Mario Fierro
Mario Fierro taught social science at Cathedral Catholic High School. Photo Credit: Cathedral Catholic High School

A man accused of killing his ex-girlfriend’s fiance — a Cathedral Catholic High School teacher — by shooting him outside his North Park home was ordered Wednesday to stand trial on a murder charge.

Jesse Milton Alvarez, 31, is accused in the Feb. 1, 2021, slaying of 37-year-old Mario Fierro, who police found shot shortly after 7 a.m. outside his home in the 4500 block of Kansas Street.

Prosecutors allege Alvarez waited outside Fierro’s home for about an hour until the victim left his residence, then shot him six times at close range. Fierro died at the scene.

The defendant was arrested that night at a relative’s home in Serra Mesa.

At Alvarez’s preliminary hearing, San Diego police Detective Ron Newquist testified that a search of Alvarez’s internet history in the months prior to the shooting revealed extensive searches related to methods for killing someone.

Some of the searches Alvarez allegedly made included, “Will a shot to the head with a 9mm Glock kill you?” and “How to kill your ex’s fiance.”

Alvarez also allegedly searched for information regarding California’s self-defense laws, how to kill someone without leaving forensic evidence, and searches regarding hiring hitmen, the detective testified.

Preliminary hearing testimony indicated Alvarez also signed up for firearms classes in the weeks leading up to Fierro’s killing.

District Attorney’s Office investigator Osvaldo Cruz testified that Alvarez asked a gun range employee during those classes, “Where is the best place to shoot someone to kill them?” followed shortly by, “What about the back of the head?”

The defendant’s internet history also included “almost daily” searches regarding his ex-girlfriend, Amy Gembara, as well as her recent engagement to Fierro, Newquist testified.

Gembara, who also taught at Cathedral Catholic High School, testified that she dated Alvarez for more than four years. She said that after breaking up with him in late 2019, “he did not take no for an answer” and Alvarez proceeded to repeatedly contact her, despite her telling him she did not want to speak with him or continue the relationship.

She alleged Alvarez called her numerous times at her work and at one point tried to break into her apartment, prompting her to move. Later on, she received mail from Alvarez at her new home, despite not giving him the address, she testified.

He also showed up at the Cathedral Catholic campus on at least two occasions after Gembara had advised school administrators that he shouldn’t be allowed on the premises. Gembara testified that in October of 2020, staff informed her Alvarez was at the school, apparently after having obtained a job in the school’s cafeteria through a third party catering company.

She attempted to obtain a restraining order against Alvarez in early 2020, but a judge denied the request.

She began dating Fierro in February of 2020, and he proposed to her in December.

Alvarez is charged with murder, a firearm-use allegation and a special circumstance allegation of lying in wait, which refers to hiding and waiting for someone with the intent of killing them. The special circumstance allegation means Alvarez could face the death penalty or life in prison without the possibility of parole.

Defense attorney Peter Blair requested that the lying in wait allegation be dismissed, arguing the prosecution had not proven that Alvarez had ambushed Fierro, and that the shooting may have resulted from a mutual fight.

According to Deputy District Attorney Ramona McCarthy, surveillance footage showed Alvarez left the Serra Mesa residence at around 6 a.m. and was in Fierro’s neighborhood not long after. Coupled with the defendant’s internet activity, the prosecutor said the evidence showed Alvarez spent “ample time meticulously searching and educating himself on how to kill Mr. Fierro.”

She also alleged that Alvarez specifically chose the date of Feb. 1 knowing Fierro would head out to work that morning, as it was the day Cathedral Catholic High School resumed in-person classes, which were previously suspended for pandemic-related reasons.