Transcript for Martin MacNeill's mistress testifies for the state at his murder trial: Part 9
On the sixth day of testimony in the murder trial of martin Macneill there was a huge amount of public interest, because that was the day that gypsy Willis was set to take the stand. The state calls gypsy Willis. And in the end the state pulled out the trump card. The mistress. My name is gypsy Willis. People wanted to hear what gypsy had to say. People wanted to see what happened when gypsy and martin Macneill, who had been separated now for quite some time, were once again together in the same courtroom. How do you know the defendant? We were involved a number of years ago. We met online. Did the relationship become sexual? It did. I think we probably had sex half the time. Sometimes it was just lunch. Gypsy was very cold on the and she responded without emotion. She didn't really own up to the inappropriate behavior that that was. You appear to be minimizing your relationship with the defendant. I don't believe so. She wasn't telling a full and complete story. A difficult person to get to engage on the witness stand. This was two years after she passed away, I don't -- I'll ask the questions, thanks. Or she was couching her story in terms that were beneficial to because she still had feelings for martin. There was one point where she lied about the extent of their relationship after they were both sent to federal prison. So you didn't have a relationship after that? After that he wrote to me while I was in jail, yes. Okay, so he wrote to you? Well, we wrote back and forth, yes. And you referred to each other with terms of endearment and such. Prison is a very lonely place. And how does he address it to you? Dear sweetheart. Would you read this line he wrote to you right there? I will work hard to keep your love for me. Gypsy Willis was forced to read her love letters in front of the jury. I love you and miss you more than you can imagine. Macneill had sat, stoic, for a large part of the testimony. But when that happened he had a visible reaction. I wish I could sleep for the next 20 months and do nothing but dream of being with you. I love you with all of my heart and think of nothing but a future with you. The jury was finally seeing the real martin Macneill. During the preliminary hearing, when she left the stand after testifying, when she walked by martin, she was touching the table and sort of dragging her fingers along the table so I think that was a clear signal to him that, martin, I still love you. I still have feelings for you. It was toward the end of the trial that the prosecution pulled out its big guns. They had a series of witnesses who had served time with martin Macneill when he was in prison for identity fraud. We've discussed previously that we're gonna refer to you as inmate number three. Is that okay? Yes, sir. The judge ruled before trial that none of the jailhouse informants' faces or names would be mentioned in court because they could get labeled as a snitch and possibly get repercussions in prison or even be murdered. Did you ever know martin? Yes, sir. Did he have a nickname? Doc. Everybody around him called him doc. According to inmates in the prison with martin Macneill he got on pretty well with the other prisoners. One time my foot was bothering me and he gave me advice on what was wrong with it. Did you guys become friendly? Yes, sir. How did that happen? I work out a lot, and we used to ask me a lot of questions about working out. Soon we started working out together. Jogged, ran, everything. Prior to Michele's death martin used to walk around with a limp and a cane, and claim that he had a bad foot because their theory was that martin was basically trying to set an explanation for why he would be physically unable to pull Michele, his wife, from the bathtub. Did he ever walk with a limp that you saw? I didn't see it. What about use a cane? No. He did a lot of different calisthenic type exercise. Well, the inmates testified that that condition, whatever it was, magically disappeared. The state may call its next witness. The state calls Jason porier. By the time trial came around he was out of custody. And his safety wasn't really jeopardized in testifying. I would have him read my poetry. He would correct it and give me some advice on how to make it better. Did martin talk to you at all about the relationship he had with his wife before she died? A little bit, yes. Do you recall what he said? That it was going downhill and that they were trying to get his money, she was not gonna let him keep cheating on her. She wasn't going to allow that. While martin was serving time for identity fraud in a Texas prison, inmates learned that he was suspected of killing his wife after watching a television show. Someone came to me and said come look at the TV real quick and they said do you recognize that guy on there? Is he in your computer class? And I said, yeah, that's doc. Do you recall what the program was? Yeah, it was "Nancy grace." The next morning I saw him coming through the breakfast line and I walked up to him and I said hey, doc, did you see TV last night? And he said no, he said don't say anything to anybody. I'll talk to you later about it. He pretty much just opened up about it. He said he gave her some oxy and some sleeping pills and then got her to get in the bathtub. Did he say what he did next? Later on he just said he had to help her out. And I asked him what that was and he said he held her head under the water for a little while. If they could prove that, you think I'd be sitting her talking to you? So I said, well, did you do it? He said the -- drowned. He said his wife drowned? Yes, sir. And he referred to her as a -- ? Yes, sir. He said I'm glad the -- is I was pretty shocked. I was very happy in large part with how the evidence came out. When we filed the case we weren't aware of the inmates' testimony at all. So it was purely circumstantial. The jury was left trying to determine who was telling the truth. Dr. Martin Macneill, appointed by the governor to run a huge medical facility, or an inmate in the texarkana federal pen? After 22 days it's time for closing arguments. The case is about to go to the jury, and a judgment will finally be rendered on whether martin Macneill is guilty of murder. All of the evidence which you hear in this case must be filtered through the proof beyond a reasonable doubt filter. Martin Macneill murdered his wife Michele. Her death was not the result of an accident and it was most certainly not the result of a heart condition.
This transcript has been automatically generated and may not be 100% accurate.