What Happened to Lauren Spierer? Five Years Later, Ex-FBI Agent Thinks He Knows Her Fate

It has been five years since Lauren Spierer vanished after a night of partying.

A new TV special is focusing on the mystery of the beautiful college student who vanished without a trace after a night of partying five years ago.

Read: 8-Year-Old Boy With Messy Room Killed by Mom's Fiance: Authorities

The mystery of what happened to 20-year-old Lauren Spierer has never been solved.

But now former FBI agent Brad Garrett and ABC’s Brian Ross say they have ideas on what may have happened to her on June 3, 2011, and are featuring her story in "Looking For Lauren," airing Friday night on 20/20.

"She was part of a wild party scene and in some way or another, drugs and students using drugs, led to her demise," Ross told Inside Edition. 

The Indiana University student was seen on surveillance video the night of her disappearance. She partied at a local sports bar and met up with several male friends.

These men have since lawyered up and are not talking about what happened that night.

One popular theory is that the co-ed was kidnapped by a biker gang after collapsing in the street on the way to her apartment.

Garrett says he does not believe she was abducted.

Instead, he says he was given information from a source that her college friends hold the key to the mystery.

“He had heard she was at a party, had a bad reaction to ecstasy, died, they panicked and moved her to the Ohio River,” Garrett said. “They're 18,19, 20 years old. The last thing they want is the Bloomington police to come in and find drugs and a dead co-ed. We believe somebody panicked and got rid of her.”

Read: Video Shows Boys Throwing Rocks at Homeless Man Seeking Shelter From the Rain: Police

Spierer was only 4-foot-11 inches and weighed 90 pounds and would have been easy prey in an intoxicated state.

Just a few months ago, the FBI dug up farmland in Indiana but didn't find her body.

Lauren 's parents have given up hope that their daughter is still alive but they still want closure.

“What they want now is to find her body and figure out what happened that night,” Ross said.

Watch: Missing Hiker Left Haunting Journal of Last Days: 'When You Find My Body, Please Call My Husband'