SAN LUIS OBISPO (CBS13) – Paul Flores, the man charged in the death and disappearance of Kristin Smart, will face a judge Monday in a highly anticipated preliminary hearing where we will hear evidence and witness testimonies.

The beginning of what’s expected to be a historic hearing is set to play out in a San Luis Obispo courtroom.

READ MORE: Mystery Man With Amnesia At UC Davis Med Center Identified Thanks To Community Tips

All eyes will be on prosecutors who will try to prove the remains of Kristin Smart were buried under the arroyo grande home of Ruben Flores, Pauls’s 80-year-old father who is accused of being an accessory to murder.

“The allegation against Ruben is that he helped to conceal Kristin’s body after the murder was committed,” Dan Dow, San Luis Obispo County District Attorney, said in a prior press conference.

The preliminary hearing is expected to be lengthy, lasting up to three weeks. A preliminary hearing allows the court to examine evidence to find out if there is enough for a trial, but they typically last 1-2 hours, not weeks.

“The prosecution is going to have to draw a line—a clear line—from where Ms. Smart was last seen, who she was seen with—Paul Flores— all the way through 25 years of when the excavation happened and what court documents have shown that biological evidence was found,” said Attorney Alana Mathews.

Investigators say Paul Flores was the last one to see Smart, of Stockton, as she walked back to her dorm after an off-campus party 25 years ago. She was never seen again and her body has not been found.

READ MORE: Nevada County Man Sentenced For Decades Of Sexual Abuse

Recently, unsealed court documents revealed what investigators say was found during the March and April searches of the Flores home. Attorneys believe evidence like soil samples could be presented during the hearings.

CBS’ 48 Hours has covered Smart’s case throughout the years—at one point sitting down with her sister who sat in awe while reminiscing about how great her big sister was.

“She had traveled the world before she even made it to college by herself, which is pretty amazing,” she told 48 Hours.

Now, Monday marks the beginning of what’s expected to be a tough and lengthy trial that will be handled cautiously and methodically.

“This is a very tragic case that happened to certainly a young woman who has a very profound impact on her community,” Mathews said.

But it’s a trial that prosecutors hope will bring the Smart family closure.

MORE NEWS: New Wildfire Prompts Evacuations In Shasta County; Arson Suspect Arrested

If the judge feels there’s enough probable cause to go to trial, attorneys say an arraignment date will be set after the preliminary hearing and a possible trial date could be set well into 2022.

Marissa Perlman