"She is my hero," Vanessa Guillén's fiancé Juan Cruz tells PEOPLE. "Because of her, a lot of people are speaking up"
Vanessa Guillén's Fiancé Shares Heartbreak a Year After Her Death: 'Every Day I Pray for Justice'
Fort Hood soldier Vanessa Guillén, 20, disappeared on April 22, 2020, and was later found murdered
Ashton Kutcher to Testify at Trial of Alleged 'Psychosexual Thrill Killer' Accused of Murdering Friend
Ashton Kutcher told police that he peered through a front window and saw what he believed were red wine stains on the floor