According to the newly released documents, the man was a busboy who was working till midnight on or around July 7, 2016. He told investigators on Nov. 22, 2017 — more than a year after the encounter — that Mr. Spacey arrived at around 11:30 p.m. with his manager. After his shift ended, the two were introduced and immediately started having several drinks together. The accuser said he told Mr. Spacey he was 23, even though he was actually 18.

At one point, the two were beside a piano at the bar, where Mr. Spacey and the accuser had been singing songs. He said Mr. Spacey put his left hand on his thigh and then unzipped his pants, before rubbing his penis.

The accuser said he was not sure what to do and proceeded to send a video of the encounter to his girlfriend, whom he had been texting and who did not initially believe what was going on. Mr. Spacey left to go to the bathroom and the accuser, who said he was distraught, left to go home.

The criminal complaint includes interviews with other people, including the accuser’s girlfriend, who told the authorities that the Snapchat video showed Mr. Spacey “touching the front” of the accuser’s “pants by his crotch.”

A bartender who was working at the Club Car that night told detectives that he remembered Mr. Spacey being there with the accuser but did not see any sexual assault.