An ex-convict was found guilty yesterday in the rape and torture of a Columbia University graduate student who survived 19 hours of nightmarish sadism in which he scalded her with boiling water and attempted to blind her before trying to burn her to death.

Robert Williams was convicted of attempted murder, rape, kidnapping, arson, and other charges in the attack, which was so prolonged and agonizing that the victim begged her tormentor to kill her and later tried to kill herself.

The verdict followed a gruesome trial that included dramatic testimony from the victim.

Williams, who was found guilty of all but two of 46 counts, was not in court to hear the verdict read. The judge said that when he was told a verdict had been reached, he simply turned over in his courthouse cell and went back to sleep.

Williams, who previously served eight years in prison for attempted murder, faces life in prison when he is sentenced July 24.

The defense attorney, Arnold Levine, said Williams had been uncommunicative throughout the case and showed no emotion when he was informed of the verdict in his cell.

“Basically he didn’t say anything,” Mr. Levine said. “He didn’t have any more reaction to that than he has had to anything else.”

The victim and her relatives sat in the front row of the courtroom while the verdicts were read but showed no reaction. Her father, on behalf of the family, later declined to comment.

When the trial began June 5, an assistant district attorney, Ann Prunty, told jurors that Williams had violated the victim “in every way imaginable — and in some ways unimaginable,” then tried to finish her off by burning her alive.

The evidence against Williams included DNA from the victim found on a shirt he was wearing when he was arrested and DNA from him on one of the woman’s T-shirts. His DNA was also on the victim’s iPod earbuds Ms. Prunty said he kept as a “trophy.” The victim also identified him in court.

The woman told teary jurors Williams repeatedly raped and sodomized her, scalded her with boiling water, threw bleach at her eyes in an attempt to blind her, and slit her eyelids during the excruciating torture in her upper Manhattan apartment.

She said Williams made her swallow fistfuls of painkillers from her medicine cabinet, ordered her to gouge out her eyes, sealed her lips with Krazy Glue, gagged her with duct tape and hanged her by her arms in a painful position in a closet so that her feet could not touch the floor.

The woman said Williams tried to withdraw her money from ATMs but refused to write down the personal identification numbers, forgot which number went with which account, and failed to get any cash. Frustrated, he returned and attacked her again.

Ms. Prunty credited the victim’s intelligence and mental toughness with helping her survive, despite the emotional and physical pain. She said the woman, who was a journalism student, began deliberately making mental notes.

The victim testified that when she saw Williams gathering her electronics and other things as if preparing to steal them and leave, she thought she might come out of the ordeal alive.

She said she started memorizing features and scars of her torturer while trying to connect with him — even asking about his taste in music — and trying to convince him she wouldn’t identify him to authorities.

Tied up and left unconscious to die in a fire her attacker set in her apartment, the woman woke up and used the flames to burn through some of her restraints and escape what might have become her crematorium.

Ms. Prunty said Williams fled when his victim fell unconscious because he no longer had the sadistic pleasure of hearing her cry and scream when he hurt her.

The nearly three-week trial was unusual in that the defendant was in court just once for a few hours. He was forced to show up on the day the victim testified and pointed him out to the jury as her rapist and torturer.

During pretrial motions and hearings, Mr. Levine tried unsuccessfully to have Williams declared mentally unfit to stand trial. The lawyer said Williams consistently refused to speak to him or mental health professionals.