? ? "20/20's" "Murder for hire" continues. Once again, David Muir. Reporter: Already behind bars for trying to kill his wife, Guillermo vasco is still trying to finish the job. He's hired a hit man,... See More
? ? "20/20's" "Murder for hire" continues. Once again, David Muir. Reporter: Already behind bars for trying to kill his wife, Guillermo vasco is still trying to finish the job. He's hired a hit man, or so he thinks, to silence her for good, and he knows exactly how he wants it done. He wanted her to suffer before she was killed. And he wanted to know the last thing she said before she died. Reporter: So, he didn't want this fast? No. Reporter: He's going to pay for the kill with his coin collection. He wants her shot, stuffed in a barrel, dumped at sea, but he wants cement. He even brings up the Laci Peterson case, saying he doesn't want to make the same mistake as that guy Scott Peterson. But I don't want to have happen what happened with this guy Peterson. Nah, I know what you're talking about. He was an idiot. That's not how I do business. I said, "Do I look like an amateur?" "I am an expert." "The body will never be found." Reporter: But that hired gun ken is actually working undercover for someone else -- the ATF -- along with agent Matt o'shaughnessy on the outside, about to pull the trigger a plot of his own, even more colorful than Guillermo's. So, you approach his wife? We did. Reporter: And what did you ask her? I told her of the plan that her ex-husband, or soon-to-be ex-husband, wanted her killed. Reporter: Was she surprised? Shocked. Shocked at the -- the thought that part of her life was behind her. How long was it before she said, "Listen, I'm in. I'm going to help you"? Within minutes. She wanted to nail her husband? She did. Reporter: So, what did you do? We had hired a movie makeup artist to make her up like she'd been shot. It's something straight out of the movies. Reporter: So we go to the very same apartment in this quiet Massachusetts suburb where the police have a small field office. None of the neighbors knowing that behind this door that wife was getting a makeup job she would never forget. Detectives help us reconstruct that day with a stand in for the wife. So, as she's sitting in this chair, the makeup artist is crafting a bullet wound in her forehead? Yes. And -- and what is her demeanor? Very quiet, you know, just kind of going along with everything. She knew what she was doing? Yeah. I mean, she had to do it. She really had no choice. I mean -- I mean, she did but -- but for the safety of herself and her child -- she knew that she had to do it. Reporter: With a lifelike bullet wound right in her forehead, fake bruises and scratches on her hands Mrs. Vasco and sergeant Mcdaid drive to the woods for a scene straight out of a horror movie. Mrs. Vasco looking so graphic they have her cover herself with a hood, afraid they would frighten other drivers. So, she wore a hood to cover up the make-up while you were driving? Yeah. Reporter: Because people who looked in the car would think you'd just beaten her. Remember Guillermo wants his wife murdered deep in the woods, which is right where they're headed. We came down here. Walked down this path. So you bring her out here and you ask her to do what? Well, she was asked to lay in different positions. Reporter: Again they reconstruct that. To make it look like a struggle. Reporter: You actually took her shoe off? Yes. Reporter: And mixed her in with the leaves? Mixed her in and -- and then she laid there and had her -- had her picture taken as if she had been killed. Reporter: It was the performance lif here, but in the end too close to home. Right when it was all done, she just let go and she cried and -- and really she -- she just released every emotion. Reporter: And it's not over yet. Now armed with the grisly photos of a dead wife, it was time for ken to go undercover again as the hit man. So, you've got these photographs now and you're headed back to the jail, how realistic do these images look to you? Very realistic. They -- I mean, it looks like this person was tortured, beaten and murdered. Reporter: Ken is now back at that prison about to show Guillermo what he's done. And when you show those images to him? I tell him, "Well, listen, you know, it's done, and here it is." And I slide a picture across the table and show it to him. Reporter: And just watch right here, the smile beginning to appear on gullermo's face. This sick grin comes across his face. No remorse, no nothing. It was just pure evil. It really was. There was joy and evil in his face at the satisfaction of knowing that she was dead. Reporter: What did he say? He wanted to know that I let her know that this was for guillero. Reporter: He wanted you to say that? Yes. "This was for Guillermo"? Yes, and I told him that's exactly what I did. Reporter: And take a closer look as that husband casually looks at the photos of his dead wife. At one point, we hear him ask about the hole in her head. What's this? So, how do you like the work? Speechless. Reporter: He wanted to know if that was a bullet wound? Yes. He nodded in approval. Reporter: He nodded in approval that you'd shot her in the head? Yes. Okay, so this is a good day for you. Everything is moving forward. I really appreciate the job. Wish I could see it. I mean, be there. Thank you. He gave him an undying respect and loyalty for what he had done. Reporter: So, there was no question he was pleased? No question whatsoever. Reporter: He thought his plan was carried out? Yes. Reporter: Armed with everything they need, the undercover team is about to return to that prison with their own surprise for Guillermo. At first, telling him his wife has disappeared. He denied any knowledge of where she could be. Reporter: Was he concerned at all that his wife was missing? No. No, he didn't show any emotion towards it. He kept saying he didn't do it. He didn't know what they were talking about, and so they decided to bring me in. Reporter: And when you walked into that room with your badge hanging around your neck? You could just see his shoulders slump, his head kind of drop down. He was shaking his head. Tears started coming out. And he knew he had been had. Where were the tears for his wife? There were no tears for his wife. Those tears were for him. He realized he was going to jail for a long time. Reporter: Good work. And as for the wife who had long ago washed that gruesome make-up off her face, she was finally ridding herself of the husband who had hoped that bullet hole was real. She saw the video. I mean, she saw it, you know? She saw her husband? Yes. Reporter: Still a doctor, still raising that daughter. I -- I can't say it enough. She -- she really -- I mean, she's a hero and -- she's just an amazing woman, very -- very
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