Dominique Pelicot is France’s most infamous predator. He admits that he surreptitiously drugged his wife for almost a decade so that he could rape her, and that he invited dozens of strangers he met online to violate her limp, snoring body.

And yet, for more than three months, Mr. Pelicot, 72, has sat in the courtroom where he is on trial with 50 other men and painted himself as the honest one. The rapist among 51 rapists, he says, who had the courage to deliver the truth on what they all did. The one who loved his wife and family desperately but, after 40 years of resisting, was overcome by perverted impulses.

He is also the one who had nothing left to lose: He said he expected to receive a maximum sentence and spend 20 years in prison after the verdict is delivered this week.

“No one belongs to anyone else, but I did what I wanted when I had the urge,” Mr. Pelicot said one day during the trial, leaning back in his chair in the prisoner’s box, the same gray fleece jacket he had worn every day zipped up. “That’s what’s at the heart of this story.”

He told the court that he had felt remorse the mornings after he drugged his wife, Gisèle Pelicot, but that had not stopped him. “The next day was terrible, because I saw what a bad state she was in,” he said, “but I won’t complain today, because that would be indecent. She is the one suffering, not me.”

During the trial, the judges and lawyers in the court in the French city of Avignon tried to grasp the enigma that is Mr. Pelicot, with only modest success.