A 21-year-old Arizona man who was engaged to his former high school teacher has been sentenced to 10 years in prison for fatally stabbing a romantic rival.

Sixto Balbuena was convicted of second-degree murder for killing 18-year-old Samuel Valdivia last year after finding him at the Chandler home of 49-year-old Tamara Hofmann, who was his supposed fiancee. The two began dating when Balbuena was Hofmann's student at Tempe's Marcos de Niza High School. Police reports show Balbuena found Hofmann naked and Valdivia wearing only boxer shorts.

After several hours of questioning, Balbuena admitted he flew into a rage and killed Valdivia. he was sentenced Friday by Maricopa County Superior Court Judge Christopher Whitten