Jurors spent several hours yesterday poring over sexually explicit online chats between a UPMC radiology resident and a special agent for the state attorney general's office who was posing as a 13-year-old girl.

The doctor, Kenneth J. Tolman, 50, of Ross, is on trial, accused of having three unlawful online exchanges with an agent from the child predator unit.

Dr. Tolman is not practicing medicine while the case is pending, his lawyer said. He faces three counts each of unlawful contact with a minor, criminal use of a computer and criminal attempt.

Defense attorney Alexander Lindsay Jr. told the jury in an opening statement that he didn't contest that the defendant went online and chatted and transmitted sexually explicit Webcam videos of himself to an undercover agent.

He said Dr. Tolman did not believe he was communicating with a child. He thought it was an adult posing as a child, his lawyer said.

A 42-inch plasma screen television displayed for jurors the text of three Yahoo! "Romance" chats between the pair, as Special Agent Lisa D. Ceh decoded the teenage vernacular line by line:

LOL, laughing out loud; BF, boyfriend; Y, why; TY, thank you; TTYL, talk to you later.

Some of the other terminology was easier to discern. The defendant said his name was Bob Robertson, age 38, from Wexford. The agent said she was Kaylee Miller, age 13, from Cranberry, and fond of wine coolers. According to an online profile the agent set up, Kaylee's hobbies were "cheerin, dancin, swimmin, skatein, hangin wit my peepz and checkin out the guyzzzzzzz."

During the chat, the agent sent actual photographs of herself at the ages of 12 and 13. The defendant wrote in graphic language to the agent about sex acts and on three occasions transmitted real-time, sexually explicit video of himself.

He stated in chats that he wanted to meet her and they discussed where and when they would meet. They never met. Instead, investigators traced the online account to an apartment rented by Dr. Tolman.

Deputy Attorney General William F. Caye II asked to show jurors the explicit videos sent by the defendant.

Mr. Lindsay argued that the prejudicial nature of the videos outweighed their value as evidence.

Allegheny County Common Pleas Judge Jeffrey A. Manning said he would rule this morning on whether to screen the videos for the jury.