STEUBENVILLE, Ohio — In a case that came to light through social media, the second day in the trial of two high school football stars accused of raping a drunken 16-year-old girl was dominated by text messages unveiled Thursday by the prosecution, recounting the night of the alleged rape and the aftermath.

A state forensics investigator, Joann Gibb, methodically quoted from text messages that she said came from the phone of one of the defendants, Trent Mays, 17, and from the phones of friends and classmates. The messages described the inebriated girl as “dead” or as a “dead body” and stated that Mr. Mays acknowledged penetrating the girl with his fingers.

For the prosecution, the text messages were a way to project a real-time accounting of the night. Defense lawyers say that anything that happened between the girl and Mr. Mays and his co-defendant, Ma’lik Richmond, 16, was consensual.

Mr. Mays and Mr. Richmond were members of Steubenville High School’s powerhouse Big Red football program. They were charged days after photographs and social media postings involving the episode appeared online.