Two married professional bodybuilders pleaded not guilty Thursday to killing their live-in assistant and torching her body in the desert.

An alleged accomplice, Anthony Gross, also pleaded not guilty to charges alleging he helped Craig Titus and Kelly Ryan burn Melissa James' body, which was found early Dec. 14 in the trunk of Ryan's burned-out Jaguar off a highway southwest of Las Vegas.

Defense lawyers said after the brief arraignment that they intend to seek bail for Titus and Ryan, whose trial was set for Jan. 22.

Titus, 41, a 1996 bodybuilding champion and Mr. Olympia competitor, stood in shackles and declared himself "100 percent not guilty" when asked for his plea to charges of murder with a deadly weapon, first-degree kidnapping and third-degree arson.

Ryan, 33, a past Fitness America, Fitness International winner, faces the same charges.

Prosecutors have not said whether they will seek the death penalty.

The grand jury charged Titus and Ryan after prosecutors presented evidence that James, 28, was drugged, bound, shocked with a stun gun and strangled. Gross, 23, was charged with accessory to murder and third-degree arson. He posted $13,000 bail and is under house arrest.

Titus initially told police he had had an affair with James. Later, Titus and Ryan told police they evicted James after discovering she was stealing from them. They said she stole Ryan's car.

Police said the couple also said James overdosed on drugs and they panicked and burned the body for fear publicity about the death would hurt their careers.

Titus and Ryan were arrested Dec. 23 at a nail salon in Stoughton, Mass. Police accused them of fleeing to avoid prosecution; their lawyers said they were visiting friends for the holidays.