Transcript for Prosecution recounts graphic stories of assault by Harvey Weinstein in criminal trial
Reporter: The downward fall of movie mogul Harvey Weinstein has been a very long and very public saga. For both him and the more than 80 women who have accused him of sexual misconduct. I thought no meant no. Literally I will never be the same. Reporter: Today is the day both Weinstein and his alleged victims have been anticipated. Opening arguments in his criminal trial. Weinstein is facing five felony charges which include rape and sexual assault. There are two counts which accuse him of being a sexual predator. Those are the counts that could put him behind bars for life. Reporter: Weinstein has denied all the allegations, saying any sexual relations were consensual. In November I sat down with Donna Rotunno, a member of Weinstein's defense team. You're currently defending what many would regard the most hated man in America. Why are you defending him? Number one, Harvey has a right to defense. I am not the moral police on Harvey Weinstein. But that's not my job. And frankly, it's not the jury's job either. The jury's job is to determine whether Harvey Weinstein committed a crime that will put him in prison for the rest of his life. Reporter: For many in the "Me too" movement, including some of Weinstein's accusers like rose Mcgowan, this trial is a watershed moment. The trial means so much to so many, but it will mean the most to the brave women testifying and to all of us silence-breakers. Reporter: Despite Weinstein's dozens of accusers, the trial will focus upon allegations of only two women, Mimi haleyi, who says Weinstein forced himself on her in 2006 when she was working as a production assistant. Women has a right to say no, and no is a no regardless of the circumstances. Reporter: And an unidentified woman who alleges Weinstein raped her in a hotel room in during today's opening statements, prosecutor Megan hast recounted to the jury in detail the stories of six women who will testify as witnesses in Weinstein's trial. It was graphic. It was intense. It was moving. We're going to see some very uncomfortable moments as we go forward. Reporter: Hast referred to Weinstein as a sexual predator and rapist who overpowered women, making them feel nervous, upset, in some cases unable to fight back, laying there motionless, like a dead fish. During the defense's opening statement one of Weinstein's attorneys argued that the prosecution's allegations were untrue. Damon torones told jurors the prosecution's arguments were a preview to a movie we're not going to see. Reporter: The defense says they had friendly emails these women engaged in after the alleged assaults including I love you, I always do, but I hate feeling like a booty call. Dozens of loving emails. Reporter: He believes they could raise doubt. There's direct communications between Harvey and the women, always friendly, sometimes romantic, that would lead any reasonable person to think that the claims are untree. There are plenty of experts out there who say it's fairly well documented that a lot of times when women are assaulted, will communicate with the person they accuse because they're trying to normalize something traumatic that happened to them, and that this isn't unexpected behavior. There are some doctors that will say that. We will discredit the fact that there is no research to prove that. Reporter: In a statement to ABC news, Mimi haleyi's attorney Gloria Allred says once the jury understands the context of the minimal communications by my client, Mimi, they will understand why they were sent and that communication after an assault does not mean that no assault took place. We've seen time and time again where sexual assault victims maintain some relationship with the perpetrator and it's not unusual. Reporter: To make this point in court prosecutors will call upon forensic psychiatrist Barbara Ziv. This expert will provide context for the prosecution. It helps explain why the accusers did certain things and didn't do certain things based on her experience and expertise dealing with sexual assault Reporter: During the course of the trial, which is expected to last several weeks, the prosecution and defense will present their arguments to a jury made up of seven men and five women. Inevitably you're going to think that the prosecution wants more women, but that's not necessarily true. Women may judge women more harshly. Reporter: Because much of the evidence in the case is a he said/she said, the prosecution will call upon four prior bad acts witnesses to show that Weinstein allegedly demonstrated patterns in his behavior. It's difficult because you don't have a smoking gun, you don't have DNA, you don't have fingerprints, you don't have video, all the things that we go to court with every day. It's really going to be based on these women who are going to testify against him. Reporter: Prior to bad acts witnesses were also called by the prosecution during the second Cosby trial. Bill Cosby was not convicted in his first case, when no other women were allowed to testify. He was convicted in his second trial when additional witnesses were permitted. Reporter: The strategy of Weinstein's legal team, which includes Rotunno, will be to undermine the credibility of these witnesses, among them actress Annabella schiarra. She says he shoved her onto the bed, locked her arms over her head, and raped her while she kicked and screamed. Annabella has told so many different stories. Her first line of conversation about this was nothing ever happened with Harvey. Then it evolved and the story kept changing. She says the chances of charging Weinstein publicly would change her life permanently, and she wasn't prepared to face that because of all the scrutiny. There was real intimidation going on. Did they feel intimidated or were they more concerned about what could potentially happen to them, and were they willing to play a game that they then decided they weren't willing to play? Reporter: In a statement her lawyer Gloria Allred said, Annabella is very coureous, she will testify under oath, when she does the jury will understand what she alleges Weinstein did to her. Many of the dozen women who allege crimes against Weinstein are unable to bring their criminal cases to court because they are beyond the statute of limitations, signed ndas, or are otherwise ineligible. The M.O. Is eerily similar in all of these cases. You have windows in a bathrobe with the promise of a career boost, or he's asking for a Going to a hotel room and having someone ask you if you'll give them a massage is not rape. It's not sexual assault. And it's really not even sexual harassment. People have a right to make a pass, and you have a right to say, no, thank you. Even if you're in a position of power? But you're not in a position of power when someone wants something from you. It doesn't mean you want to nest give Harvey Weinstein a massage or see his naked body. There's many things that lead up to that point. And those are the things that people don't want to say when they come forward and make these claims. When someone in a position of power over someone else's career makes the pass with the explicit or implicit promise of career benefits, that is the very definition of sexual harassment. There are people who say, here you have a woman defending Harvey Weinstein, have you been accused of being a traitor to your own gender? I don't believe I am. I think in many ways I would hope that I could help women. What happens in these circumstances where women don't want to take certain responsibilities for their actions, we infant lies ourselves. You have to know when you make certain choices there's a risk when you make those choices. A lot of people would say what you just said is victim blaming. And that's absolutely not true. If you don't want to be a victim, don't go to the hotel room. If you don't want to be a victim, don't sign the nda. Go onto fifth avenue, take a megaphone, talk about what you want to talk about. Blaming victims who take a settlement to someone for not going out and talking about it is absurd. Do you ever worry that maybe you'll be on the wrong side of history on this one? No. I don't. And I think what I worry about is the outcome for him. I don't worry about the outcome for me. Reporter: As for Weinstein, the charges in this case are not the only criminal charges he is facing. On January 6th, in California, prosecutors announced new charges against Weinstein for raping a woman in a Los Angeles hotel room in 2013 and sexually assaulting a second woman the following night. One of those women is expected to testify in the New York case. Now the question remains, will the fallen Hollywood power broker also lose his freedom? Are you going to jail, Mr. Weinstein? Reporter: His alleged victims await an answer. For "Nightline," I'm Amy robach in New York.
This transcript has been automatically generated and may not be 100% accurate.