High School Student Killed In Love Triangle Involving Teacher

An 18-year-old Chandler, Arizona high school student caught with his 48-year-old math teacher in her bedroom was stabbed to death by her boyfriend, who was himself a former student of hers.

Chandler police say 20-year-old Sixto Balbuena told them he never meant to kill Samuel Valdivia. "The blade went in like going into butter," said Balbuena. "I just wanted to show Valdivia how much he hurt me by sleeping with Tamara Hofmann.

Balbuena, a Navy sailor on leave from California, was arrested after police found him covered in blood and told them about the killing. He is charged with second-degree murder and remains in jail in lieu of $100,000 bond.

Balbuena found his girlfriend naked and Valdivia in his boxer shorts in Hofmann's bedroom around 2:40 a.m. Friday, according to police reports and court documents.

Balbuena told police that Valdivia apologized to him before Balbuena began kicking, punching and throwing things at him, according to a police probable cause statement. "I wanted to teach him a lesson," said Balbuena.

Balbuena stabbed Valdivia in the lower side with a kitchen knife. Valdivia later died at a hospital.

Balbuena also threw Hofmann to the floor, jumped on top of her, and demanded to know how long she had been cheating on him, according to documents.

Hofmann was Valdivia's math teacher at El Dorado High School in Chandler and was also Balbuena's teacher when he attended Marcos de Niza High School in Tempe.

Balbuena is the one who called 911. He told officers he felt remorse for stabbing Valdivia after seeing him lying on the floor struggling to breathe.

Hofmann is being investigated for potential misconduct relative to her involvement with Valdivia.

A 2006 Chandler police report states that police suspected Hofmann of having a sexual relationship with a then 17-year-old Balbuena. Both Hofmann and Balbuena denied being in a sexual relationship, and police closed the case.

D. Brian Blackwell