An ex-convict accused of raping and torturing a graduate student for 19 hours should be convicted of attempted murder because he tried to burn her alive to stop her from identifying him, a prosecutor told jurors yesterday.

The blaze in the Columbia University student’s upper Manhattan apartment was set as the finishing touch on what an assistant district attorney, Ann Prunty, called Robert Williams’s “one-man, 19-hour crime rampage.”

“He intended that her whole body go up in flames,” Ms. Prunty said in her closing arguments.

If the student had been a minute or two slower in escaping, the prosecutor said, this would have been a homicide case.

But Mr. Williams underestimated the victim, who used the fire to burn her bonds and free herself from what almost became her crematorium and survived to identify Mr. Williams to police and later to jurors at his trial, Ms. Prunty said.

Earlier, a defense lawyer, Arnold Levine, told the jury there was no concrete evidence that Mr. Williams started the fire or attempted to kill the woman.

“If that man’s conscious objective was to cause her death, she’d be dead,” Mr. Levine argued.

Ms. Prunty said the victim’s identification of her attacker in court was proof enough to convict him but the case also includes DNA evidence and witnesses who said they saw Mr. Williams enter the building the day the attack began.

Mr. Williams, 31, was tried on 71 counts that included attempted murder, kidnapping, arson, rape and sodomy, committed, Ms. Prunty said, after he forced his way into the woman’s Hamilton Heights apartment on April 13, 2007.

A state supreme court justice, Carol Berkman, said she would submit only 46 of the counts to the jury before it begins deliberating today because some weren’t supported by the evidence and others were duplicative. Mr. Williams faces life in prison if convicted.

Mr. Levine told jurors it was meaningless that the student had pointed out the defendant in court because anyone can see who’s sitting at the defense table.

Ms. Prunty responded: “You don’t get a better opportunity to observe somebody than being with them for almost 19 hours.”

The prosecutor cited the repeated sexual attacks recalled by the student and told jurors, “There isn’t an inch of his body she doesn’t see.”

Ms. Prunty said the woman, realizing she might survive the ordeal, memorized Mr. Williams’s scars and features — including his gold tooth — and was able to give descriptions of them to police several days before he was captured.

“The DNA evidence in this case is like the icing on the cake — you don’t need it,” Ms. Prunty added.

She said the victim’s blood was found on a shirt Mr. Williams was wearing when he was arrested and his DNA was found on one of the victim’s shirts.

“It is now time to hold Robert Williams accountable for what he did, not just because we are reviled, horrified, shaken and shocked by what he did,” Ms. Prunty said, “not just for revenge or retribution and not just for sympathy and compassion for the victim but because that is what the evidence dictates.”

Mr. Levine told jurors that if they find Mr. Williams was the torturer, they should consider that the defendant has a mind that “doesn’t work in a rational way.”

Mr. Levine had tried unsuccessfully to have Mr. Williams declared mentally unfit to stand trial.