Mario Fierro was a teacher at Cathedral Catholic High School. (Photo courtesy diocese)

After deliberations of six hours over two days, a jury convicted a man Monday, March 11 of first-degree murder in killing a teacher, Mario Fierro, in North Park, who was the fiancee of the man’s ex-girlfriend.

The eight woman, four man jury also found the special circumstance true that Jesse Milton Alvarez, 33, was lying in wait for Fierro, 37, outside his Kansas Street apartment before shooting him six times on Feb. 1, 2021.

This finding means San Diego Superior Court Judge Daniel Goldstein will likely sentence Alvarez to a life term in prison without the possibility of parole.

Goldstein set sentencing for May 10. Alvarez remains in jail without bail.

“Closure feels good, at least as far as this part of the procedure goes,” said Deputy District Attorney Ramona McCarthy said afterwards. “Nothing will bring Mr. Fierro back.”

Fierro was a beloved teacher at Cathedral Catholic High School and was engaged to another teacher, Amy Gembara, who had ended a relationship with Alvarez in 2019.

The prosecutor used evidence from Alvarez’s computer searches to show jealousy as a motive for murder. His searches included “How to shoot someone in self defense;” “how to commit the perfect murder;” “how to shoot your ex-girlfriend’s fiancee;” “what does a woman do with her engagement ring if her fiancee dies,” among others.

Alvarez’s attorney, Kerry Armstrong, told jurors Alvarez was diagnosed with autism only after his arrest and that he did not understand social cues very well, as a reason behind his stalking behavior toward Gembara. Alvarez on the stand said he was also diagnosed with obsessive compulsive disorder.

Alvarez told jurors he met Gembara in June, 2015 on a dating app and was “heart broken” when the relationship ended four years later.

Armstrong told jurors Alvarez felt it was his role to protect his ex-girlfriend when he saw photos of her drinking alcohol after her engagement was announced.

“I was kind of obsessed. I, uh, I’m kind of in my own world,” said Alvarez on the stand. “I couldn’t shake it out from my head, like my desire I had to be with her, to talk with her, to help her. I just felt kinda betrayed.”

“There was this post that announced their engagement. I was super shocked,” testified Alvarez. “I…I couldn’t take the hint. It went over my head. In retrospect, these (computer searches) are some really weird searches. I probably should (have) deleted those.”

The defense argued that Alvarez fired in self-defense after a struggle over the gun, but with the jury’s verdict, they rejected that theory.

“He tried to hit me. He got his fingers around the trigger and he pulled it and the gun discharged and I screamed and I was afraid,” said Alvarez, who was on the stand for over five hours over two days.

“I shot him in the back,” said Alvarez, at one point, adding that Fierro stood on his knees and “rushed me again.”

Alvarez underwent vigorous cross examination from McCarthy.

“You’re the one who killed Mr. Fierro, right?” asked McCarthy.

“Yes, I’ve testified to that,” replied Alvarez.

“You put six bullets in his body, correct?” asked the prosecutor.

“Yes. I understand that,” replied Alvarez.

“You put two in his forehead, right?” asked McCarthy.

“Yes,” said Alvarez.

“And you put two in the back of his head, right?” asked the prosecutor.

“Right,” answered Alvarez.

Alvarez quarreled with McCarthy over the first shot, saying “the first shot was in the arm. I was there.”

In her rebuttal argument, McCarthy told jurors Alvarez has “methodically plotted out (Fierro’s) execution.”

“And frankly, it’s insulting—it’s insulting…that the defendant is claiming this is self-defense,” concluded the prosecutor.

KGTV reporter Brian Hill caught up with Armstrong afterwards and asked him if he regretted any trial strategy or putting his client on the stand, given the outcome.

“I don’t think there is anything we would have done differently,” said Armstrong. “I still think it was the right call (for Alvarez) to take the witness stand, tell his side of the story.”

Testimony began Feb. 26.