Was a beauty queen-turned-teacher murdered by a former student from her school?

Years after Tara Grinstead vanished, another student came forward with a startling story.

The Tara Grinstead Mystery
The Tara Grinstead Mystery 41:33

To this day, the disappearance of 30-year-old Tara Grinstead mystifies the small community of Ocilla Georgia, known for its friendly small-town America values and vast pecan orchards.

And for more than a decade, pecan orchards held the secret of what happened to the one-time beauty pageant contestant, who was enjoying a successful career as a teacher.

"48 Hours" correspondent Peter Van Sant investigates the young woman's disappearance and the quest for answers in the case he's covered for 12 years in "The Tara Grinstead Mystery."    

On the afternoon of Saturday, October 22, 2005, Tara had helped younger contestants prepare for a local beauty pageant.  Afterwards she went to a barbecue. Sometime around 11 p.m. she returned to the small house where she lived alone.

When she failed to show up to teach her history class on Monday morning at Irwin County High School, her friends knew something was wrong. "She would never do that, she would never leave her kids," said her best friend Maria Woods Harber.

Maria went to Tara's home and noticed her car in the driveway. She followed police inside. Tara's purse and keys were missing, her alarm clock was under the bed and a bedside lamp was broken — but there was no other overt sign of a struggle.

Investigators received hundreds of tips, but nothing panned out. But in 2017, a woman named Brooke Sheridan came forward with a remarkable story.  She said her boyfriend, Bo Dukes, appeared to have been keeping a secret from her.  She prodded him to confess what had been eating away at him.  Finally, she says, he told her his secret: that years earlier his roommate Ryan Duke [similar name, no relation], woke him up one morning and told him he had "accidentally" killed Tara after trying to rob her in her home. The two men had attended Irwin County High School. In fact, Bo had been a student in one of Tara's classes.

Bo Dukes and Ryan Duke
After Bo Dukes, left, went to the GBI, Ryan Duke, right, was arrested and charged with Tara's murder. Bo was arrested weeks later on charges relating to covering up the crime.  AP/Georgia Bureau of Information

Bo said that Ryan told him he had used Bo's truck to transport her body to a pecan orchard owned by Bo's family. Later, Ryan showed Bo the exact location where he had dumped Tara's body. Bo told Brooke he helped Ryan burn Tara's body in a fire pit, which took two days.

After Bo told his story to authorities, Ryan Duke was arrested and charged with murder. Bo Dukes was also arrested and charged  -- not with murder --  but on charges related to helping to cover up a crime. He was convicted and sentenced to 25 years.

Ryan has pleaded not guilty and is now awaiting his day in court. But no matter what the outcome of that trial, many people, including Maria Woods Harber, have questions about Bo Dukes' version of events: that Ryan alone killed Tara and Bo had only helped burn her body.

"I believe that Ryan and Bo Duke were both in this together. I've had to come to a conclusion that I'm just gonna have to live the rest of my life not knowing.

"What happened in this orchard was senseless…" says Woods Harber. "Two men who had no regard for a beautiful, loving person took her life."