The 73-year-old defendant -- who was the subject of the 2015 HBO documentary The Jinx -- offered his plea in a Los Angeles courtroom on Monday, after he was extradited from Indiana.
"I am not guilty. I did not kill Susan Berman," Durst said at the hearing.
After Durst's plea, the Los Angeles District Attorney announced that it would not seek the death penalty. Durst will be held without bail and a preliminary hearing is scheduled for Feb. 15, 2017.
Earlier this year, Durst pleaded guilty on a firearms charge, and was sentenced to seven years and one month in prison after a .38-caliber revolver was found in his New Orleans, Louisiana, hotel room in March of 2015.
Durst's murder case gained national attention on The Jinx finale, when Durst was heard saying on a hot mic, "What the hell did I do? Killed them all, of course."
The docuseries focused on the several investigations Durst has been connected to.
The initial one dates back to 1982, when Durst's first wife, Kathleen, was reported missing, and hasn’t been seen since. Durst has long been suspected by many to be behind the disappearance, which he has repeatedly denied.
Then in 2000, Durst's longtime friend, Susan Berman, was killed execution-style in her Beverly Hills home. Before her death, Berman allegedly told Durst she was to be interviewed by the police about his wife Kathleen.
That same year, Durst fled to Galveston, Texas, where he posed as a mute woman. In 2001, he was arrested for the murder and dismemberment of his neighbor, Morris Black. Though he admitted to carving up the body, Durst convinced a jury that Black’s death was in self-defense. Durst was twice acquitted of the crime.
Watch the video below for five true crime stories you really need to see to believe.