Jury members found Jesus Carrizoza-Quijada guilty of sexual assault on Friday October 28.
Late last year, at a family gathering, Carrizoza-Quijada entered a bedroom where the victim and another family member were talking.
Carrizoza-Quijada asked the other family member to leave then sexually assaulted the victim.
Carrizoza-Quijada's DNA was found of the victim's clothing after she reported the assault.
A sentencing is scheduled from December 12 of this year in the Pima County Superior Court.