In a chilling case from Arizona, a 31-year-old man, Tyler Ross McGuire, will spend his life in prison after a fatal encounter driven by obsession and jealousy. The tragic incident unfolded as McGuire, the manager of a pizza shop, became increasingly fixated on a female employee. His infatuation turned deadly when he targeted a male colleague, Deazo Seghi, whom he believed was vying for the same woman’s affections.

The Maricopa County courtroom saw McGuire receive a life sentence without the possibility of parole for the murder of Seghi earlier this year. In a definitive conclusion to this unsettling case, a jury found McGuire guilty of first-degree murder, a verdict that underscored the gravity of his actions.

“This defendant carried out a planned and unprovoked killing, leaving a family to endure an unimaginable loss,” stated County Attorney Rachel Mitchell. She emphasized that the sentence not only delivers justice to the victim’s family but also sends a powerful message that such violent acts will face the harshest penalties as dictated by law.

Details from a news release from Mitchell’s office reveal McGuire’s growing obsession with a female subordinate at the pizza shop located in Mesa, Arizona. This unhealthy fixation culminated in the murder of his fellow employee, a tragic endpoint to a dangerous infatuation.

According to a news release from Mitchell’s office, McGuire grew “fixated on a woman he supervised” at a local pizza shop in Mesa, Arizona, where Seghi was also employed.

“McGuire told the woman he had a crush on her, but she made it clear she was not interested,” the release states. “That same month, McGuire physical[ly] confronted the victim, believing he was also pursuing a relationship with the woman.”

Prosecutors said that over the course of the next year, McGuire grew increasingly angry with the victim, escalating to the point that he “purchased a gun and searched for the victim’s address.”

About a year after McGuire initially confronted Seghi about the woman, Seghi was gunned down in front of his home.

“On December 11, 2023, the victim was found slumped over inside his vehicle in front of an apartment complex near North Stapley Road and East Brown Road in Mesa,” prosecutors wrote. “According to witnesses, McGuire approached the vehicle and shot the victim multiple times in the chest before running away.”

McGuire was quickly located and taken into custody. At the time of McGuire’s arrest, police said they found a cellphone and black handgun in his possession. The bullets from McGuire’s handgun came back as a match for the bullet casings found at the scene of Seghi’s murder.

Several days after McGuire’s arrest, his mother contacted authorities regarding a diary she found that belonged to her son. The diary “detailed” McGuire’s “plan to kill the victim” as well as his “reasoning for doing so.”

One entry read: “I decided a while ago I needed to kill someone. This person hurt me.”

Another said: “If I had my way, I’d be with her. Although that opportunity was stolen from me.”