-- Flanked by his attorneys, Los Angeles Lakers guard Kobe Bryant stood before a Colorado judge Tuesday and firmly declared himself "not guilty" of felony sexual assault, setting the stage for a criminal trial next fall that could send the 25-year-old athlete to prison for life.

State judge Terry Ruckriegle said he is not yet ready to set a date for the trial, because legal and scientific arguments about evidence in the high-profile case are unresolved. But Colorado's speedy trial law says that a trial must start within six months of a plea -- that is, by Nov. 11 in Bryant's case -- unless the defendant asks for a delay.

The not-guilty plea, nearly 11 months after the sexual encounter at a mountain resort that sparked the criminal charges, came as no surprise. Bryant has acknowledged having sex with an Eagle woman last summer, but he says it was consensual.

The surprising development at Tuesday's hearing was the announcement that prosecutors do not plan to introduce any evidence at the trial of other sexual activity by Bryant. Prosecutors in rape cases frequently seek to strengthen their case by showing that the defendant was sexually active. The absence of such evidence could help Bryant's legal defense, legal analysts watching the case said, and will also spare him potential embarrassment in a trial that will be covered by cable television networks and seen worldwide.

The TV cameras were running Tuesday in Eagle County's small rural courthouse when Ruckriegle turned toward Bryant, sitting silently at the defense table, and said, "We are ready to proceed to arraignment." A criminal arraignment is the proceeding in which a defendant is officially informed of the charge against him, and asked to enter a plea. The arraignment has been pending for months as lawyers argued over evidentiary issues.

Bryant, in a black suit, white shirt and gold tie, lifted his lanky frame to the lectern before the judge, with an attorney on each side. Mindful of the cameras, defense attorney Pamela Mackey asked the judge not to read the charge out loud. But Ruckriegle read it, anyway:

"That on or about the 30th of June in the County of Eagle, State of Colorado, Kobe Bean Bryant unlawfully, feloniously, and knowingly inflicted sexual intrusion or sexual penetration. . . . The defendant caused submission of the victim through the actual application of physical force or physical violence."

The judge asked Bryant if he understood the charge. "Yes, sir," the defendant replied quietly. Next the judge asked for a plea. As his attorney, Mackey, wrapped her arm around his back, Bryant replied "Not guilty" in the same clear but quiet tones.

Minutes later, Bryant strode out of the courtroom and set out, with his omnipresent staff of bodyguards, for a private jet back to Los Angeles, where he played against the San Antonio Spurs in a National Basketball Association playoff game Tuesday night.

The trial that has overwhelmed this rural village in the windswept Rockies stems from an incident last June when Bryant checked into a mountain resort. A 19-year-old hotel clerk told police the next morning that Bryant had invited her to his suite and then raped her. If convicted, Bryant faces penalties ranging from 20 years of closely supervised probation to a prison term of four years to life.

Bryant has hired a prominent criminal defense firm in Denver and a large team of investigators, scientists and forensic experts to assist his defense. The defense has made it clear that its chief trial tactic will be an aggressive attack on the credibility, mental stability and morality of the alleged victim. The defense has launched a blizzard of motions seeking evidence about the woman's medical, psychological and sexual history. Legal arguments on these motions have dragged on for eight months.

Before Bryant entered his plea Tuesday, attorney Hal Haddon asked the judge to overturn the Colorado rape shield law. That statute, similar to those on the books in every other state and in the District, says that evidence of prior sexual activity by a woman alleging rape generally cannot be entered into trial. Haddon said that the Bryant defense wants to introduce evidence about the sexual background of the woman who accused Bryant, and that the shield law violates a defendant's constitutional right to confront his accuser.

Ruckriegle did not rule on the motion, but reminded Haddon that the Colorado Supreme Court has ruled the rape shield law is constitutional.

Kobe Bryant of the Los Angeles Lakers leaves court with attorney Pamela Mackey after entering a not guilty plea to sexual assault charges in Eagle, Colo. If convicted, Bryant could be sent to prison for life.