Last Updated Jun 12, 2017 8:52 AM EDT
For the first time, the public may see surveillance video showing what happened inside a Penn State fraternity house before a student died.
died after several falls down the stairs at the Beta Theta Pi building. He reportedly drank a large amount of alcohol during a hazing ritual that night.
The fraternity -- along with 18 of its members -- faces criminal charges.
Today's preliminary hearing will determine whether the 18 brothers, as well as their fraternity, should stand trial. The, which allegedly show Piazza's agonizing final hours at the frat house, are a key part of the prosecution's case.
"The videotape is horrible, and it is gruesome," said Piazza family attorney Tom Kline. He says the family hasn't decided whether they'll be in the courtroom when the surveillance videos are played.
"No parent wants to see what is apparently on this videotape," Kline said.
The videos were recorded by security cameras inside the Beta Theta Pi house on February 2, and have never been seen publicly.
According to the grand jury presentment, around 9 p.m., the videos show Piazza and other pledges in a ritual called "the gauntlet," consuming large amounts of beer, vodka and wine in a matter of minutes.
Shortly after, Piazza apparently fell head-first down the basement stairs. When he reappears on camera, carried by fraternity brothers, his body is limp and his abdomen clearly bruised.
"These videotapes will undoubtedly show the various acts which are spelled out in the grand jury report," Kline said. "The dragging of a young man, failing to attend to him, punching him, and other acts which appear in the grand jury report to be indefensible."
Around 5 a.m., the cameras captured Piazza falling head-first into an iron railing. Shortly after 7 a.m., he apparently fell down the basement stairs again.
The fraternity brothers didn't find him for another three hours -- and then waited 42 minutes to call 911.
Piazza died one day later. A pathologist said he had severe head trauma and a ruptured spleen.
Attorney Rocco Cipparone Jr., who represents Michael Bonatucci (who faces eight charges in Piazza's death), said, "I know the Bonatucci family and Michael in particular, certainly feel empathy and sympathy for the Piazza family. But sadly, just because someone passes away doesn't mean that everybody in the room is responsible."
Prosecutors have filed a variety of charges, including involuntary manslaughter, hazing, and tampering with evidence.
Last month the fraternity said it does not tolerate hazing or alcohol abuse, adding the defendants are entitled to the presumption of innocence.
UPDATE: On Monday a spokesperson for the fraternity told "CBS This Morning," "As these hearings begin, Beta Theta Pi International Fraternity has confidence in the judicial system that due process and justice can and will be served.
"We will continue to cooperate with authorities in all manners to make sure of it."