DEDHAM, Mass. — Dirk Greineder turned in his chair and gave reassuring looks to his adult children several times in court Wednesday but otherwise displayed no emotion as prosecution witnesses testified about his secret pursuit of paid female escorts and use of online services to meet women.

Greineder, 60, is not charged with any sex-related or obscenity crimes. But the once-esteemed Boston doctor's sexual interests are major issues as he defends himself against charges that he murdered his wife of 31 years on October 31, 1999.

The day before and the day after Mabel "May" Greineder was bludgeoned and stabbed to death, Greineder used his cell phone to call a paid escort but never got her on the phone. The woman, Deborah Doolio, testified that she had a "meeting" with Greineder in the spring of 1999 but suggested that September that they not see each other again until he found "peace within himself."

By proving that Greineder called Doolio, an admitted prostitute, the day after the murder, prosecutor Richard Grundy seems to be trying to convince the 14-member jury that the defendant found the peace he may have been looking for when his 58-year-old wife was pronounced dead in the woods at the Morse's Park Recreation Area in Wellesley.

Greineder insists he did not kill his wife and his lawyer contends that the testimony of Doolio and others about Greineder's sexual interests is being offered by the prosecution because they don't have much of a case. The testimony, however, comes on the heels of expert testimony about physical evidence that links Greinder's DNA to a bloody glove found in a storm drain along with a knife and a 2-pound hammer used to killed Mabel Greineder.

Doolio took the stand Wednesday morning after Judge Paul Chernoff ruled that her face not be shown on Court TV, which is broadcasting the trial, or by any of the Boston television stations drawn to the murder trial now in its thirteenth day.

Speaking in soft tones, Doolio was conservatively dressed in a navy blue suit as she raised her right hand and gave the oath to the tell truth. Removing a black handbag slung over her left shoulder, the 40-something witness with short brown hair worn in a bob looked like she could have been an executive secretary as she took a seat and waited for the first question.

Grundy established quickly that Doolio worked occasionally as an escort and accepted cash for sex. He never, however, specifically asked Doolio if she had sexual relations with Greineder or if any money changed hands.

"I'm not sure of that date, but it was in the spring [of 1999] and I did meet with the gentleman named Dirk," said Doolio, who was reminded several times to speak up.

Greineder called Doolio the next day to thank her, according to testimony, and she did not hear from the defendant the rest of the spring and the entire summer.

"I received a phone call around September. The gentleman mentioned he would like to meet again," Doolio testified, her voice cracking at times. "Discretion was very much a priority ... for the sake of his children."

Greineder's three adult children — Britt, 28, Colin, 25, and Kirsten, 29 — wore blank expressions as Doolio talked about their father's desire to keep his relationship with the escort a secret.

Doolio went on to describe a conservation with Greineder that led her to conclude that he was troubled by something.

"It was contemplated by the gentleman whether he wanted to meet again and he seemed very confused and indecisive," Doolio said. "I felt confused and I told him maybe that seeing an escort wasn't the best thing to do for him until he found some peace within himself, but I would be available if he needed me or desired to see me at a future time."

The entire courtroom was silent as Doolio told the jury of eight men and six women about the last thing Greineder told her.

"I remember receiving a phone call call after that. The gentleman told me not to call again because it wasn't the right time," Doolio said. " 'Now wasn't the right time.' "

Mabel Greineder's older sister, Isle Stark of New York, clenched a tissue and sobbed as defense attorney Martin Murphy conducted his cross-examination of the witness. Murphy elicited from Doolio that she gave police investigating the murder a statement only after one of the officers posed as someone seeking her services as an escort, met her in a motel parking lot and escorted her to a police station.

After the morning break, the jury heard from representatives of two Web sites that cater to adults seeking other adults for dates, relationships or sex. Greineder used the services to place and respond to ads from women seeking sexual partners, according to testimony. There was no testimony that the doctor ever arranged to actually to meet any of the women.

A representative of a third Internet service, Yahoo! Inc., testified that Greineder used the alias "T. Young" to register for a free e-mail account on Oct. 20, 1999. Greineder used his own name as well as the alias of Thomas Young, the name of an old college friend, to obtain a credit card that was later used to place calls to phone sex services, a witness testified previously.

Murphy, the defense lawyer, got the witnesses who work for the adult Web sites to estimate that thousands of people visit their sites each day. Throughout the trial, he has argued that evidence that Greineder paid for sex and online interaction with other adults is not evidence that he had a motive to kill his wife.

Nonetheless, Grundy called a parade of witnesses to underscore his contention that Greineder was leading the secret lifestyle. Two women testified Wednesday, for example, that each received e-mail messages from Greineder, using the handle "casual_guy2000," in response to their postings in search for partners.

Katherine Irwin and Joanne Nichols both read aloud e-mails from Greineder stating that he was looking for an "uncomplicated relationship."

Another witness, Harry Page, told the jury that "casual_guy2000" traded naked photographs with Page's wife, Amy, and expressed interest in arranging group sex at a hotel.

"I am married but she does not play, so I am looking for a couple to play with," Greineder wrote Page, who read the e-mail out loud. "I'm basically straight but can be flexible in group situations."

Page, who was permitted to testify off-camera by the judge, said no such session ever occurred. Page, a portly man with brown hair and beard, left the courtroom through a rear door and was kept from reporters.

In one of the numerous e-mails to Page, Greineder explains his "preferences have remained very vanilla — if you call threesomes vanilla."

Before venturing into the salacious testimony about Internet sex talk, bondage and domination, picture trading and group sex proposals, Grundy told the jury that the prosecution and defense were stipulating that a paid escort named Nora Lopez visited Greineder at a New Jersey hotel about a week before the murder and had sex.

The stipulation was made so that Lopez would not be required to testify in court.

The trial is being broadcast by Court TV.