The trial of a French surgeon who for years sexually abused hundreds of patients, most of them minors, enters its final phase on Monday with the accused’s lawyers set to make their closing arguments.

Joel Le Scouarnec, 74, has admitted to sexually assaulting or raping 299 patients in hospitals in western France between 1989 and 2014, many while they were under anesthesia or waking up after operations. Of those patients, 256 were aged under 15 at the time.

The prosecution on Friday requested the maximum 20-year sentence for the former surgeon and also made the rare demand that he should be held in a center for treatment and supervision even after any release.

“You were the devil and he sometimes is dressed in a white coat,” prosecutor Stephane Kellenberger told Le Scouarnec, adding that an additional trial could be required to cover the cases of further victims whose abuse is not part of the current case.

The verdict from the court in Vannes in the western Brittany region is expected on Wednesday. But before that, his defense lawyers, whose meticulous and respectful conduct has won praise throughout the trial, will put their case.

Le Scouranec is charged in this trial with 111 rapes and 189 sexual assaults and is set to emerge this week as one of the most prolific convicted sex predators in France’s history.

One of the surgeon’s lawyers, Maxime Tessier, said last week that his client was “utterly guilty” and the defense is expected not to cast any doubt over the gravity of his crimes.

But they may seek to argue that the contrition of the former surgeon, who apologized to his victims, is genuine and that he has undergone personal evolution behind bars.

However many victims’ lawyers questioned the sincerity of Le Scouarnec’s apologies, which he repeated almost mechanically over the weeks of the trial, sometimes word for word.

“I am not an actor,” responded Le Scouarnec after a lawyer for one of the victims expressed irritation over his frequently monotone answers.

While the surgeon admitted responsibility, he also repeatedly said he did not remember his acts.

But Tessier said his client had acted throughout the trial in a way that was “respectful” of justice and that his admittance of guilt was “not posturing” but marked a genuine “evolution.”