(CBSNews) LOS ANGELES -- A Canadian man pleaded not guilty Tuesday to charges of torturing, mutilating and killing a girlfriend whose bloodless body was found in their Southern California apartment.

Blake Leibel, 35, could face the death penalty if convicted of first-degree murder in the slaying of Iana Kasian, prosecutors said. The LA Times reports Leibel is a comic book creator, animation director and screenwriter from a prominent Canadian family.

Kasian's mother had reported her missing. Deputies discovered her dead body Thursday after forcing their way through a door that Leibel had barricaded with furniture. Lt. Dave Coleman of the Los Angeles Sheriff's Department told the paper he seemed "agitated and uncooperative."

Prosecutors say Leibel is believed to have killed the woman sometime between May 23 and May 26. Kasian, 30, appeared to have been badly beaten at some point over the past three days, and all the blood had drained from her by the time she was found, authorities said. Leibel was arrested at the scene.

The couple were reportedly new parents of a baby girl. CBS Los Angeles reportsthe child was born four weeks before Kasian's murder. The child is reportedly safe and in the care of relatives.

Authorities told the station Kasian's cause of death was blunt force trauma. The station spoke to neighbors of the couple who said they heard screaming from the apartment, but thought it might have been a television so no one called authorities.

"This is a serious matter," defense attorney Alaleh Kamran in a statement issued by publicist Howard Bragman to the Los Angeles Times. "Mr. Leibel's defense team request that the public and the media respect his right to a fair hearing in court."

A week before the body was found, Leibel was arrested on suspicion of sex assault, the paper reports. He was booked May 20 and released later in the day on $100,000 bail, according to jail records. He was reportedly never charged in that case.

The Times reports Blake Leibel worked as a director and consultant on the animated series "Spaceballs," based on the 1987 film by Mel Brooks. Canada's National Post reports Leibel is the son of Lorne Leibel, a Canadian Olympian and prominent real estate developer.

Leibel, according to Mokayef, is being held without bail. He is due back in court June 14.