Transcript for Penn State hazing death: Former fraternity brothers face new charges
Authorities say they have new evidence, including intentionally deleted video. New information in the Penn state death of Tim piazza. We have new evidence. Surveillance video that authorities say was destroyed is now recovered by the FBI. This is the video that they clearly did not want seen. Guess what, guys. Now we know. They say the footage from the beta theta pi house show them giving the pledge 18 beers in an hour and 22 minutes. It's awful what a coordinated effort that this crew took upon themselves to get Tim and the other pledges so drunk for the reason of becoming part of their organization. I am glad that the basement video was recovered and we finally know what went on down there. That was the whole defense argument, we don't know. Piazza's parents reacting to the new charges in this interview. Reporter: At this point, have you been able to watch that video or are you just not doing that? I think we're just not doing that. Now new charges against a dozen former fraternity bothers, bringing the total to 26. They say on that night, piazza and 26 other pledges took part in what they call the gauntlet. Piazza suffered a catastrophic fall, 15 feet down a flight of stairs. The grand jury reports say no one called 911. Instead, previously released video captured hours of piazza in distress, the injured college sophomore trying to get up and repeatedly falling over. Four men are seen dragging his limb many BP body upstairs by slapping his face and pouring water over him. This member tried to get him the help he needed. I was saying we should take him to a hospital and call an ambulance, dial 911. It's nice that he had good intentions at the time but I don't know why anybody didn't pick up a phone. Instead of dialing 911, the report says the brothers were using their phone to search for the phrases "Ifalling asleep after head injury" and cold feet and cold hands. What's going on today? Ah, we have a friend that's unconscious. He hasn't moved, probably going to need an ambulance. Back in may when I spoke to his parents, they said by the time they saw him in the intensive care unit, he was almost unrecognizable. He was all covered up with warming blankets. We were trying to find skin to touch. The nurses told me to tell him good-bye. It was hard. That's what you think of when you close your eyes. It looked like he got hit by a car. He was in bad shape, he was on life support. He wasn't there. The nurse brought me in a room to see them and they broke it to me that he wasn't going to wake up ever. Piazza died from his injuries the next day. Medical experts estimate his blood alcohol content at the time of the fall was 0.4. During a preliminary hearing in July, prosecutors say they had evidence that members of the beta theta pi chapter had withheld key information, including these text messages allegedly, changed between the frat brothers. One reads "He looked Dead." Another "I think we are , like beyond ." After this, I think we could get kicked off. I don't want to go to jail for this. One brother allegedly urged another to delete a group message that included piazza S there would nobody evidence on Tim's phone. Another writing, "Make sure the pledges keep quiet about last night and this situation." These fraternity guys thought that by erases text messages or erasing their searches on their internet browser that they would prevent law enforcement from finding that information, but the reality is that once a text message is sent, once an internet search is conducted, that information can't just disappear. Prosecutors say the frat brothers thought they could make the basement videqs disappear, too. They claimed the videos weren't working and police worked with the FBI to recover the missing video. That studio now charged with tampering with evidence. There was a text message where nor individual had been talking with that person about deleting it. There's no question it was intentionally deleted. That will come out in the hearings. The D.A. Said the discovery unravels the previous defense claim this was all social drinking. We know for a fact that no one else -- that Tim was not getting his own drinks and that the brothers were continuing to furnish them. They are refiling voluntary manslaughter. All 14 men previously indicted have denied the charges. ABC news reached out to all 12 of the new defendants. Only one of them responded, denying any involvement. I think there's been a lot of questions at universities in the last several years about hazing and what it means and who's you have young people, you have people drinking, stories change, stories are not always reliable. Despite the pain and the heartbreak, Tim piazza's parents hope their son's story can help make hazing a thing of the past. Talk to your children. Tell them not to get involved in this nonsense. And if you're potentially one of the people that are about to get hazed, just walk away. Have friends with you and make a pact and walk away. Your life is too important to put it on the line for a brotherhood or a sisterhood.
This transcript has been automatically generated and may not be 100% accurate.