Man Accused of Murdering Nurse Denies All Charges : Courts: Mark Scott Thornton faces a special allegation that, if proved, could send him to the gas chamber. The hearing receives heavy media attention.

In his first court appearance since he was accused of murdering Westlake nurse Kellie O’Sullivan, 19-year-old Mark Scott Thornton pleaded not guilty Tuesday to all of the charges in a 14-count criminal complaint.

Before the shackled teen-ager walked into Ventura County Municipal Court, his two attorneys advised him of the intense interest in his case, evidenced by a crush of media representatives in the courtroom.

“He was warned,” Deputy Public Defender Susan R. Olson said later. “He knew what was facing him.”

Thornton stared straight ahead and seemed not to flinch at all of the attention until he was out of sight of the courtroom gathering.

Olson said Thornton broke down in tears after being led to a holding cell.

Tuesday’s court appearance may be Thornton’s last for some time. At the request of the defense team, Judge Arturo F. Gutierrez set Dec. 14 for a preliminary hearing to decide whether there is enough evidence to bring him to trial.

However, Deputy Dist. Atty. Peter J. Kossoris said he might seek a grand jury indictment, which would make a preliminary hearing unnecessary.

Thornton, also known as Mark Sarrazin, was charged Monday with the 14 criminal counts. They include a charge of murder and a special allegation that, if proved, could send him to the gas chamber. Because of the death-penalty possibility, Gutierrez denied bail to Thornton.

Police say Thornton kidnaped O’Sullivan on Sept. 14 and fatally shot her before stealing her car. He has also been charged with abducting his ex-girlfriend, 16-year-old Stephanie Campbell, the same day and shooting at Stephanie’s mother in the process.

Five days later, Thornton was apprehended in Reno, Nev., after Stephanie slipped away and notified police. O’Sullivan’s car was recovered in Reno at that time, and her body was discovered amid brush in the Santa Monica Mountains one week later.

Wearing a standard blue jail uniform and a white T-shirt, Thornton stood silently as defense attorneys petitioned the court on several motions. The judge granted one motion that asked that the court refer to him by his real name, Mark Scott Thornton, and not the name he has used in several past criminal cases, Mark Scott Sarrazin.

Gutierrez also granted a defense motion to require that Thornton be represented by an attorney whenever authorities interview him. Several jail employees have questioned him about his case, Olson said outside the courtroom, and she wanted to make sure he did not feel compelled to answer such questions.

Thornton’s mother, Markita, attended the arraignment. But she left immediately afterward without making any comment.

Nine television crews were at Tuesday’s arraignment, including one from the nationally televised program “America’s Most Wanted.”

Olson said that if public interest in the case continues at its feverish pace, the defense may ask that the trial be moved from Ventura County.

She said there seemed to be intense public anger over O’Sullivan’s death. “And since Mr. Thornton is charged with this, that anger is now focused on him,” Olson said.

Still, prosecutor Kossoris said details of O’Sullivan’s murder won’t be divulged until the case progresses in the courtroom. Prosecutors also have instructed other sources in the case, including O’Sullivan’s family and friends, not to comment.