Cosby didn't testify a year ago when the first trial took place, and after four days of defence witnesses, Mesereau made it clear his client would not be taking the stand to answer claims he drugged and raped Andrea Constand at his home in Philadelphia in 2004.
Cosby also didn't testify in the first trial previous year that ended in a mistrial.
Whether the encounter occurred in January 2004 is important because, beyond Constand's credibility, there is the issue of Pennsylvania's 12-year statute of limitations for filing charges.
Cosby is charged with three counts of aggravated indecent assault - all stemming from Andrea Constand's allegations that he knocked her out with three pills he called "your friends" and molested her at his suburban Philadelphia mansion in January 2004. He says it was consensual.
Jurors heard testimony from 25 witnesses over the course of about two weeks.
The star defense witness was a former colleague of Constand who says Constand spoke of leveling false sexual assault accusations against a high-profile person for the objective of filing a civil suit.
Prosecutors are highlighting gaps in Bill Cosby's travel records.
But prosecutors say there are multiple stretches of time that month when the comedian wasn't aboard his private jet or performing around the country.
District Attorney Kevin Steele sought to show that Cosby could have used other modes of transportation to travel to Philadelphia. They quizzed Roslyn Yarbrough, an assistant for Cosby's then-agent at the William Morris Agency, who made it clear the busy comic was at his Philadelphia-area home "very rarely" throughout the month.
Jurors in Bill Cosby's sexual assault retrial won't hear old deposition testimony from a confidante of his chief accuser, a judge ruled Monday, dealing a blow to his lawyers' effort to undermine her credibility.
Both juries also heard from Cosby himself, via an explosive deposition he gave in 2005 and 2006 as part of Constand's civil suit against him.
Cosby's lawyers said they expected Williams' testimony to refute Constand's claims that she was unaware he was romantically interested in her. In it, Williams allegedly claims that Constand planned to extort Cosby for money by accusing him of sexual assault.
Judge O'Neill rejected a defence request to call a private investigator as a witness to piece together flight schedules, itineraries and phone calls to show Cosby was out of town at the time he is accused of the attack at his home.
Cosby was charged for the drugging and assault of Constand at the end of December 2015, so if the encounter had happened earlier than January 2004, he could not be prosecuted under Pennsylvania law.
The Associated Press doesn't typically identify people who say they're victims of sexual assault unless they grant permission, which Constand has done.
Cosby is on trial for the alleged drugging and sexual assault of numerous women throughout his career as an entertainer.
Last week, defense witness Marguerite Jackson told the court she believed Constand, her former co-worker at Temple University, wasn't telling the telling the truth about her alleged encounter with Cosby.