Pittsburgh — The jury that will decide whether Bill Cosby is guilty of sexually assaulting a woman at his Philadelphia-area home 13 years ago began taking shape Monday as five jurors were seated during a lengthy opening day of the famed entertainer’s trial.

The dueling over jurors, which is set to continue Tuesday, offered some hints at what each side is hoping the panel of 12 jurors and six alternates will look like. Defense attorneys angled to block young white women from the jury, and the prosecution kept an African American woman from being seated.

Cosby watched attentively as Judge Steven T. O’Neill individually questioned a parade of potential jurors who took seats at the same table where Cosby sat just a few feet away. Still, at one point Cosby raised his hand and asked court officials to instruct jurors to speak up.

The 79-year-old comedian and actor is accused of drugging and sexually assaulting Andrea Constand, a former Temple University women’s basketball team staffer, in 2004.

Three white men and two white women were eventually seated on the jury. The jurors, whose names were not disclosed, range from an elderly man who entered the courtroom leaning on a cane to a woman who said she is a mother and appeared to be in her 30s or early 40s. Each side can block seven jurors from being empaneled, and the process quickly began to resemble a chess match as attorneys tried to decide which potential jurors to strike.

The emotions of the mostly tense day peaked late in the afternoon when prosecutors huddled to try to decide whether to use one of their seven strikes to block the seating of a middle-aged African American woman who said she’d formed some opinions about the case from watching media coverage. While the prosecutors spoke in hushed tones, Cosby laughed so hard that he had to hold his hand over his mouth.

When prosecutors announced their decision to keep the black candidate off the jury, Cosby defense attorney Brian McMonagle frowned in an animated fashion and shook his head, staring out to the audience of reporters gathered in the cramped courtroom with its wheezy air conditioner. Legal experts have speculated that Cosby — who has said racism played a role in his prosecution — might benefit from having blacks on the jury.

Montgomery County, Pennsylvania, prosecutor Kevin Steele seemed surprised at the fast pace, saying to a court security guard at a break: “We’ve got five jurors. Didn’t think we’d get this far.”

Pretrial publicity is one of the biggest challenges facing the defense as they size up potential jurors gathered in this large downtown courthouse, which resembles a medieval castle. One third of the 100 potential jurors said Monday that they’ve already formed an opinion about the comedian’s guilt or innocence.