(CNN) Deliberations began in Bill Cosby's trial on charges of aggravated indecent assault on Monday night after prosecutors and defense attorneys made their final pleas to the jury.

In a fiery closing statement, defense attorney Brian McMonagle said the prosecution's key witness, Andrea Constand, had too many inconsistencies in her story to be a reliable witness.

But District Attorney Kevin Steele said those inconsistencies were minor and little more than a distraction. He argued that Cosby used his role as a mentor and respected public figure to gain Constand's trust and then drug her and take advantage of her.

Cosby, the famed comedian, did not testify in his own defense, and his defense rested after calling just one repeat witness for further questioning.

Jurors did hear Cosby's side of the story, though not in his voice. Last week, police detectives read aloud his statements to police in 2005 and in his civil deposition in 2006 responding to the allegations. Cosby has pleaded not guilty to three charges of aggravated indecent assault.

The three charges accuse Cosby of assaulting Constand without her consent, assaulting her when she was unconscious, and assaulting her using drugs to substantially impair her ability to consent. He could face up to 10 years in prison for each charge.

Jurors were bused from Pittsburgh to the Montgomery County courthouse outside Philadelphia and sequestered in hotels during the trial. The jury began deliberating about 5:25 p.m. and asked the court one question around 7:15 p.m. and another at 9:30 p.m.

Jurors stopped for the day after four hours of deliberations and will return to court Tuesday morning.

'They're your friends'

The prosecution rested its case on Friday after calling 12 witnesses to the stand. Their central witness was Constand, the former Temple University employee who says Cosby drugged and sexually assaulted her in January 2004.

Constand testified in firm and clear words over two days last week that Cosby, a powerful alum at the university, mentored her and then took advantage of her at his home in the suburbs of Philadelphia. She testified he offered her three blue pills that he said were herbal and would help her relax.

"Put them down, they're your friends. They'll take the edge off," Cosby told her, she testified. "I said 'I trust you.' I took the pills and I swallowed the pills down."

She became incapacitated and felt "frozen" and told him so, she testified. Cosby then placed her on the couch and sexually assaulted her without her consent, she said. Cosby lowered and shook his head in the courtroom as she spoke.

In statements to police and in his civil deposition, the comedian known as "America's Dad" admitted he gave Constand pills and then engaged in sexual contact with her. He also said he had previously obtained Quaaludes, a powerful sedative, with the intention of giving them to women with whom he wanted to have sex.

Cosby's defense attorneys argued that his sexual contact with Constand was part of a consensual relationship between the two. They said Constand's initial statements to police were full of inconsistencies that undermine the truthfulness of her story.

Other witnesses in the trial included Constand's mother, a woman who accused Cosby of an assault in 1996, police detectives, and experts on drugs and sexual assault.

Cosby said before the trial that he did not plan to testify because of what could happen on cross-examination. In criminal trials, the onus is on prosecutors to prove guilt beyond a reasonable doubt, and defendants are not required to take the stand.

Closing statements

Andrea Constand walks to the courtroom during Bill Cosby's assault trial.

In his closing statement, McMonagle told jurors that Constand had changed her story after speaking with attorneys who specialize in sexual assault cases.

Constand initially told police she had not been alone with Cosby before the alleged assault and that she had little contact with him afterward. However, Constand admitted under oath that she had been alone with him before, at his hotel room at the Foxwoods casino, and phone records showed that the two had made 72 calls to each other afterward.

Constand said she was "mistaken" when she made those statements to police. She testified that nothing romantic happened in the hotel room, and that she made those phone calls as part of her job at Temple.

"Hopefully, you will have the last two words in this case, and I pray those words are not guilty," McMonagle said to the jury.

For the prosecution's closing statement, Steele argued that Cosby's own statements showed his guilt. He admitted to giving her pills without telling her what they were, and he also admitted to penetrating her genitalia with his fingers, Steele noted.

Cosby's prior use of Quaaludes with women, Steele argued, show that he had knowledge of what he was doing when he gave Constand those pills.

Steele also said the former district attorney's decision not to charge Cosby in 2005, when Constand first came to police, was a failure.

Though dozens of women have accused Cosby of sexual misconduct, Constand's accusations are the only ones that have led to criminal charges. One other accuser, Kelly Johnson, testified in the trial as prosecutors sought to establish that Cosby had a pattern of assault.

Johnson, who worked at the William Morris talent agency, said that in 1996, Cosby gave her a pill that incapacitated her and then he sexually assaulted her.

Cosby arrives with wife

Bill Cosby arrives for his assault trial with his wife Camille Cosby and publicist Andrew Wyatt.

Cosby arrived at court arm-in-arm with his wife, Camille, on Monday, marking her first appearance at the trial.

Cosby has previously arrived at the Montgomery County Courthouse with various celebrities from the world of entertainment. The former actor was joined last Monday by Keshia Knight Pulliam, who played Rudy Huxtable on "The Cosby Show."

Camille Cosby is the first member of his family to join him in arriving at court. His daughters have not done so.

As always, Cosby was also joined on Monday by Andrew Wyatt, his longtime publicist. Wyatt said on Friday that Camille Cosby continued to support him, despite the accusations of assault from dozens of women. "Mrs. Cosby has been supporting Mr. Cosby for the entire time they've been together for 53 years," he said.

"People think that because of optics that if you don't see them here, then they don't love you and you're not together anymore. That doesn't say that you don't have the support. What it says is that you want to protect your family from being attacked by this media circus out here, and that's OK."