Transcript for Why Legal Experts Say Case Against Kayak Murder Suspect May Not Hold
vargas. It's much easier now. Reporter: Yeah, no kidding. This is plum point, on the Hudson river. It's the very place is where Vince viafore and Angelika graswald set out on their fateful kayaking trip. Angelika and Vince went out on this river. Yes. Reporter: They launched straight from here to go straight across, you can see Bannerman's island and the castle right there across. We've come here with Todd Wright. A professional guide and outdoor instructor, he's recognized as one of the top kayak safety experts in the world. Working with us as a consultant, he's in the same make and model kayak as the one Vince owned. When you're out on the water, you definitely feel the current and the wind. We ask him about Angelika's claim that the wind and the current separated her in her kayak from Vince in the water. And when she says that she's being blown away from him and that he's being pulled in a different direction? Yes, that can happen. If he's in the water, he most likely would be going with the current and whereas the kayaks will go with the wind. Reporter: We also know the water temperature that day was 48 degrees. Correct. Reporter: How quickly after falling into water that cold do you become incapacitated? There's that initial cold response and there's panic, your heart rate increases -- Reporter: You're basically hyperventilating. Yeah, you're hyperventilating. Grabbing onto this kayak becomes very difficult. Being able to tread water or swim with any kind of efficacy becomes very, very difficult. Reporter: Back on shore, a close examination of the kayak shows something detectives may not at first have realized -- that critical drain plug -- effectively the alleged murder weapon, is not on the bottom of the kayak, it's on top. Now this is the infamous plug. It is, yup. Reporter: That prosecutors say Angelika removed in a plot to kill Vince. But this plug is what, half an inch in diameter? Just look at how large the cockpit is, that -- where the seat is, there's a lot of water that can enter that, that's a big hole. This is a really small hole. Reporter: It's a tiny hole. Remember the police theory is Vince died, because Angelika removed that drain plug causing his kayak to sink. Let's just take a look at how much water enters the cockpit. Reporter: But watch, Wright conducts a demonstration showing when waves dump water over the cockpit, almost all of it gets in the boat. But, if waves pour over that open drain hole? Very little finds its way into the kayak. About eight ounces, maybe. Reporter: And we went further, using that same kayak, with the open drain hole, and the paddle ring removed. We asked another experienced kayaker to retrace Vince's path across the river. He does it, with no trouble. The prosecution case is built on these assumptions, that removing the drain plug would cause the kayak to sink. Removing the connector ring would prevent Vince from paddling properly. And finally, that Angelika knew that without a life jacket or a wetsuit, Vince wouldn't stand a chance in the cold river. Did you remove the plug from Vince's kayak with an intent to kill him? No, I did not. Reporter: Did you remove the ring from the oars so that he would not be able to save himself? No. I didn't. Reporter: We actually performed an experiment on the river, with the plug out and with the ring missing on his oars. How did he do? Reporter: He did fine. What does that tell you? There you go. It tells me that there was a rush to judgment in this case, and I don't know why. Reporter: Neither the prosecutor nor the defense attorney are allowed to speak to us about this case, because a judge has issued a gag order. So "20/20" convened a round table of legal experts -- Brian Harris, a 20-year veteran homicide investigator in Houston, ABC news chief legal analyst Dan Abrams, and former prosecutor judge Jeanine Pirro, host of "Justice with judge Jeanine," on Fox News. Is there any scintilla of evidence that tells you she wanted him dead? I haven't heard it. I mean, maybe the prosecution's got it, but I haven't heard it. Reporter: Angelika's defense attorney once worked for judge Pirro in the westchester county d.a.'s office, but no one on our panel has any involvement in this case. Isn't it possible the entire premise of the case is based on something that isn't, in fact, true? That kayak plug is a red herring in this case. It's got nothing to do with his death. Reporter: Pirro and Abrams are convinced the case against Angelika will not hold water. It does seem like a bizarre and incredibly risky way to kill someone. The notion that you're willing to risk that the person is going to fall out of a kayak and then potentially come to your kayak and -- Reporter: And capsize you. And capsize you. You've got to explain to me how she felt that she was far more secure as a five-foot-tall miniature woman than he was. If those waves were taking him out, wouldn't she be risking that those waves would take her out as well? Reporter: Much was also said and much was also made of this quarter of a million-dollar life insurance policy that Vince had taken out. What do you think about that as a motive? It's always a motive, you know. Reporter: Money's always a motive. Let me tell you, every homicide that came through my office, we wanted to know, "Who's getting the money?" It's not an easy case for prosecutors. It's a tricky case, because the key piece of evidence that they have are her own words. And her own words are not entirely clear. She doesn't come out and say, "I did it." Reporter: But the panel agrees, the big problem for Angelika is what she does say in that interrogation. By taking that plug out you killed Vinnie. Correct? Correct. I think she makes some incriminating comments. She makes some -- Reporter: Yes, she does. She makes some statements which are not helpful to her. Reporter: "I'm glad he's dead" is certainly not a helpful thing to say for your own case. And a problem for the defense. I think it is. Reporter: Do you agree? Completely. I think it's a huge problem for the defense. How'd it make you feel when he did some of these things to you? Angry. Frustrated. To the point that you wanted him dead? Did you feel like this was the only way out? Yeah. It's really gonna come down to the skill of the prosecutor. How well is the prosecutor gonna be able to dissect that interview and say, "Look at what she's doing here, and what she's saying." Why didn't he have that plug in there? He didn't have it because I guess I had it. You took it out of that kayak at the one point? I might have. Reporter: So, in your opinion, this was by the book, this interrogation? I think the officers did an excellent job. I think there are things in this interview that are damning. But is it a confession? No. Reporter: I just want to ask you so, so you have a chance to answer this question. Did you kill Vince? No. Reporter: That day? No, I didn't kill him. Reporter: Did you do anything that you knew might lead to him being hurt or him dying? No, I loved him. I didn't do it. Reporter: When "20/20" continues, the evidence, photos Angelika's
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