Transcript for Police Find Video of Victim's Rape by Vanderbilt Football Players
have a problem. The Vanderbilt senior they believe is a victim of a crime has no memory of what happened to her. Surveillance video and interviews have led detectives to suspect rape. But they have no physical proof, no DNA and no suspects coming forward with a confession. So what exactly happened inside dorm room 213? Four football players, Brandon Vandenburg, Cory Batey, "Tip" Mckenzie, and Brandon banks, were alone with the woman for 30 minutes. When you spoke to these four men, did they say a rape had happened? No. Reporter: So they said they were there but nothing happened. Right. They truly thought, at that time, "They'll never figure this out. As long as we keep together, keep our mouth shut, they'll never figure this out." Reporter: But a breakthrough is imminent, thanks to an admission by a couple of other players on the team. They've seen video from a cell phone of what took place inside that room. What did you see in the video? I noticed somebody laying there. It looked like a girl just laying on the ground. Reporter: Finding the videos, now the key to the case. We knew the videos were taken. We knew many videos were taken. And the investigation shifted at that point to, "Let's put all of our effort right now into recovering the videos." Reporter: Police seize the phones and computers from the four men in the room. And it reveals a treasure trove of text messages, like this one from Cory Batey to a friend, a day and a half after the incident. "The video is gone, right?" "Nobody else knows besides you," and this one, "Video deleted?" Seems like it couldn't be more brazen of a cover-up. Completely. "Did you delete this? You delete that?" Completely. Reporter: And gish finds incriminating Google searches on Brandon Vandenburg's phone. "Can police retrieve deleted picture messages?" Brandon has reason to worry, he knows that during the attack, he sent videos to two close friends back in his hometown of palm desert, California. Four weeks after the incident, the detectives are on a plane. First stop, joey quizino, one of Brandon's best friends since age 13. He couldn't believe that we were there. But he knew why we were there. Reporter: He knew immediately. He knew. Brandon sent you some text messages and a video. Did you watch the video that he sent to you? I didn't. You didn't? No. Reporter: But friend miles Finley reluctantly admits he's seen it. Phones don't lie, man. That's why we're here. The video I got was just of this black dude playing with a girl on the floor. Playing with a girl on the floor how? Doing stuff between her legs. Reporter: After seeing the video, Finley warns Brandon in a text. "She can call rape. Delete that --" then some repulsive advice. "Dog kick that -- out or gang bang her," "Don't let her wake up." Why did you say that? I wasn't being serious. When you see something going on like that and it's a rape maybe you should call the police. Did that ever occur to you? Maybe I should tell somebody about what I just seen? I knew it would come out. Reporter: Sounds like Brandon does too. Just 30 minutes after the incident, he phones that friend joey quizino and says -- I'm in deep -- you need to call me back. Reporter: Police say that what Brandon and his friends did next was an attempted cover up. Finley claims he dropped his phone in a pool. It was cracked. Was time for a new iPhone. Did you trade it in? Tossed it in the trash? I just threw it out. Reporter: Quinzio claims his phone was stolen. Okay. Did you report your phone stolen to apple so they could shut it down? No. Reporter: But it didn't matter. Police find those elusive videos after all, backed up on quinzio's hard drive. His phone automatically synched the video to his computer. It's the nail in the coffin. Hardest thing I probably ever had to look at. And I knew right then that all of the pieces were falling into place. There she is, being raped. We just recovered the worst nightmare for this victim. Reporter: The videos show Brandon banks taking intimate and inappropriate photos of her body, and banks and Corey Batey using their hands and even a water bottle to penetrate her. And according to investigators, Brandon Vandenburg is heard callously giggling and egging the others on. All along, the four players have stuck to their plan -- deny, deny, deny. But what they don't know, players are turning on each other. Brandon Vandenburg agreed to call Corey Batey, with police recording the line. An attempt to get Batey to confess. This Is bad dude. What did they say? Dude, we are . They got videos of everything. The videos that I took of you when I was in the room, you know. Yeah. What do you mean? I'm pretty sure the video I took it didn't have you like having sex with her or nothing. But I have either you or banks Her. I don't know how much trouble you can get in for that . Reporter: Batey keeps quiet in that call. But another player has broken rank. Tip Mckenzie has caved, and he's pointing his finger at his best friends Corey Batey and Brandon banks. Corey Batey approaches the girl first as a joke. He's clowning. He's drunk. He's like "Get this on camera" he's messing with the girl. His hands down there like he is touching the girl in a sexual way. What was banks doing? Banks had the bottle. If I'm understanding you right, the only people who did anything to her with a bottle or their hands are Batey and banks? Yes, ma'am. Did Vandenburg ever touch her or participate in the clowning, touching her or anything like that? I really don't think so. I'm not sure, but what I can remember, I don't think he did. Reporter: That interview, and the videos, it's more than enough for prosecutors to make a case. Once we saw the evidence, we were just appalled. Reporter: Vanderbilt has already kicked the four players off the football team and out of school. And August 9th, less than two months after the incident they are charged with rape. Today marks day one of the trial. Reporter: Next, the trial. Contentious moments in the court. Don't look over there. Reporter: A controversial defense, blame it on the booze. Blame it on the alcohol. Reporter: And one of the defendants takes the stand and makes a shocking admission. As you just saw, the rumors are flying. Several people saw the tape of the crime taking place. Are you surprised? Tell us on #abc2020. When we come back, one defe
This transcript has been automatically generated and may not be 100% accurate.