He did not try to kiss her that night, he said, because he did not sense that she wanted him to. But he said they had a “sexual moment” at their next dinner. Their association continued for years but ended, Mr. Cosby said, when he gave her one and a half pills of Benadryl at his home to relieve stress, and they kissed and had sexual contact.

Ms. Constand described a much different course of events to investigators.

She said she had no interest in a romantic relationship with Mr. Cosby. “She never thought he would hit on her, especially since Cosby is much older than her father,” the criminal complaint said.

On the night in 2004 when Ms. Constand said she was drugged, she told Mr. Cosby she felt “drained” and “emotionally occupied,” according to the complaint. He urged her to take the pills, she told investigators.

Ms. Constand told investigators she soon had blurred vision, difficulty speaking, nausea and dizziness.

She woke up at 4 a.m. with her sweater bunched up and her bra undone, she said.

When a new wave of accusations by many women began in the fall of 2014, Mr. Cosby was trying to reignite a long-celebrated career and burnish his legacy. A stand-up comedy special on Netflix was to honor his 77th birthday. NBC was considering a project that would return him to prime time. Mr. Cosby even tried to continue a comedy tour that was interrupted by heckling and was ultimately abandoned.

But as more and more women accused him of drugging them and sexual misconduct — some filing defamation lawsuits against him over branding them as liars after they had come forward — he largely disappeared from the public eye. This month, Mr. Cosby struck back against seven of the women who had accused him of sexual assault and defamation by suing them claiming defamation. He also filed a defamation suit against another accuser, the former supermodel Beverly Johnson.

Still unclear is what impact the criminal case will have on the settlement reached in Ms. Constand’s civil suit, in which she is believed to have received a financial payment. Her lawyer did not respond to a question about that case.