OXNARD, Calif. (KABC) -- Boxer Victor Ortiz pleaded not guilty to sexual assault charges and rape at an arraignment Wednesday morning, according to the Ventura County District Attorney's Office.Ortiz, a Tarzana native and former "Dancing With the Stars" contestant, has been free on $100,000 bail since his arrest in September.In March, a woman told authorities about the alleged assault at a home in Oxnard.Following a lengthy investigation, a warrant was issued for the former welterweight champion and he turned himself in the same day. He was booked on charges of forcible rape, forcible oral copulation and forcible digital penetration, according to the Oxnard Police Department.