Donna Callahan was a 29-year-old woman from Gulf Breeze, Florida, who worked as a clerk at the Sunshine Jr. Food Store. She went missing while she was three months pregnant and had a daughter who was two years old.
Her boyfriend, Danny Knight, was out of work, and Donna Callahan recently got a job at the shop. Donna disappeared for unknown reasons on the night of August 6, 1989.
After being missing for nearly seven years, her remains were discovered in August 1996. Donna's remains were found in a wooded area near Wells' parents' property in north Walton County, Florida. The site had not been previously searched. Her identity was confirmed through dental records.
The case of Donna's disappearance had been featured in various crime documentaries, including the show Secrets in Gulf Breeze. This show is scheduled to re-air on August 23, 2025, on Oxygen.
In Secrets in Gulf Breeze, the story of Donna Callahan's disappearance is told by following clues and investigating possible suspects. The show delves into the investigation and the key individuals who contributed to solving the riddle through in-depth analysis and interviews.
A case overview of Donna Callahan's murder

Donna Callahan was last seen around 11:30 pm on August 6, 1989, while working the graveyard shift at the Sunshine Jr Food Store. She worked someone else's shift as they were sick despite being three months pregnant.
According to a WEAR NEWS report published on October 17, 2024, Donna Callahan disappeared after midnight, but someone spotted her behind the bar shortly before. Her pocketbook, keys, and automobile were left at the crime scene because the business was unlocked. The absence of a fight led authorities to believe the person had been stolen.
Despite extensive searches by local law enforcement and Donna's family, no trace of her was found initially. However, Donna's case was eerily similar to other disappearances of women working at convenience stores across Florida, with another woman, Darlene Messer, disappearing under similar circumstances in September 1989. Both cases raised suspicions of a possible serial abductor.
After years with no leads, an informant revealed that Florida prisoner William Alex Wells had confessed to killing a woman in 1993. Wells served time for assault and kidnapping. An investigation followed his assertion of Donna's disappearance.
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The search for Donna’s remains

In June 1993, agents led by FDLE Special Agent Dennis Haley went to Walton County to search the home of Wells' parents. They found a strange pile of dirt near an oil drum. A cadaver dog showed that there were human parts nearby, but after a thorough search, no body was found.
Mark Allen Riebe, Wells's half-brother, went up to Agent Haley at this point and told him that Wells had shown him Donna's body in the trunk of his car the night she went missing. Riebe also said that Wells admitted to burying her body on their family land.
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The confession and revelation

In 1995, Wells faced trial for his involvement in Donna's murder. Shortly before his trial, Wells' mother intervened, and a plea deal was arranged. Wells confessed to the murder, explaining that he and Riebe had planned to rob the Sunshine Jr Food Store.
William Alex Wells confessed to being involved in her abduction and murder. He agreed to lead authorities to the location of her body as part of a plea deal to avoid the death penalty.
After abducting Donna at gunpoint, Riebe killed her by strangulation while she begged for her life. Afterwards, Wells helped Riebe bury her body on the family property.
Two days after his confession, Wells led authorities to Donna's remains, which were found in a wooded area. The remains were confirmed to be those of Donna through dental records. Wells was sentenced to two consecutive life terms in prison as part of his plea deal.
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Mark Allen Riebe's role and further developments

Riebe, initially thought to be assisting in the investigation, was arrested and charged with Donna Callahan's murder in May 1997. In 1998, Riebe admitted to the murder, pleading no contest to first-degree murder.
According to a Daily Mail report, published on November 16, 2017, he was sentenced to life in prison without the possibility of parole. Investigators believe that Riebe, along with Wells, may have been responsible for the deaths of multiple women, though not all of Riebe's confessions have been substantiated.
The investigation into Donna Callahan's case and Riebe's confessions led authorities to uncover a larger pattern of violence and murder, revealing a chilling series of crimes across Florida.
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