A California man who Googled “how to kill your ex’s fiancé” was convicted Monday of killing a Catholic high school teacher. 

San Diego County prosecutors said Jesse Alvarez, 33, gunned down Mario Fierro as he was leaving his home to go to work at Cathedral Catholic High School on Feb. 1, 2021. He was found guilty of first-degree murder. 

Prosecutors said Alvarez killed Fierro out of jealousy after he learned the victim had gotten engaged with his ex-girlfriend, Amy Gembara, also a Cathedral Catholic teacher.

MAN ARRESTED IN CALIFORNIA IN CONNECTION TO FATAL SHOOTING OF MASSACHUSETTS WOMAN, DAUGHTER

Alvarez and Gembara broke up after 3½ years together, and he developed an unhealthy obsession, he testified, FOX 5 KUSI in San Diego reported. At one point, she changed her phone number, moved and tried to get a restraining order. 

After learning Gembara and Fierro had gotten engaged, Alvarez began plotting the murder, prosecutors said. He planned and researched how to commit the slaying by ambushing him outside his apartment. 

“‘I was brewing anger’ — his words. Yes he was. And he continued to brew anger. And what else did he say? That he wanted Mr. Fierro gone or dead,” Deputy District Attorney Ramona McCarthy told the jury. 

To plan the killing, Alvarez made several Google searches on how to get away with the murder. 

CA MOVIE THEATER MURDERER SENTENCED TO LIFE WITHOUT PAROLE FOR FATALLY SHOOTING 2 TEENAGERS

“As far as the Google searches are concerned, it definitely was a big piece of evidence in this case,” McCarthy said after the verdict was read. 

Alvarez claimed he approached Fierro and introduced himself. Fierro got angry and threatened to kill him, he said. Alvarez said he tried to calm Fierro down before pulling out a gun. 

“If this is premeditated, then he’s just shooting him right away. He’s not trying to talk to him, not trying to make conversation,” said defense attorney Peter Blair.

Fierro was shot six times — four times in the head, prosecutors said, while dismissing Alvarez’s claims of self-defense. 

“Mr. Fierro had no idea the defendant was there and no idea of his presence — had no idea the defendant waited almost an hour for him and watched him and waited right until he had his back to him. He’s a coward,” said McCarthy.

Alvarez is slated to be sentenced May 10. He faces life in prison.