Real Name: Donna Marie Susino Callahan
Nicknames: No known nicknames
Location: Gulf Breeze, Florida
Date: August 6, 1989
Date of Birth: July 30, 1960
Marital Status: Married
Characteristics: She was three months pregnant at the time of her disappearance.
Details: Twenty-nine-year-old Donna Callahan was a convenience store clerk at the Sunshine Jr. Food Store in Gulf Breeze, Florida, and the mother of a two-year-old daughter. At around midnight on August 6, 1989, she vanished while working the night shift. There were no signs of struggle at the scene. Her purse, keys, and car were left behind. Police believe that she was abducted, and possibly murdered.
Suspects: Police speculate that a serial killer may have been responsible for Donna's disappearance, along with the abductions of two other clerks, Deborah Poe and Darlene Messer.
Extra Notes: This case first aired on the November 6, 1991 episode. It was later profiled on To Catch A Killer.
Results: Solved. In 1993, investigators learned from inmates that a convict named William Alex Wells had confessed to abducting and killing Donna and burying her on family property. Wells initially denied involvement in the case. At the time, he was serving seven years for kidnapping, assault, and robbery of a convenience store. In June, investigators searched Wells' family property in Walton for Donna's remains. However, nothing was found at that time.
Wells's half-brother Mark Allen Riebe helped investigators with the initial search of the property. He later moved his family to Illinois. He was questioned repeatedly by investigators and told them that Wells was a serial killer. He later admitted to seeing Donna's body in the trunk of Wells's car and claimed that Wells had confessed to her murder. In 1995, Wells was indicted for her murder based on statements from Riebe and jailhouse informants.
In July 1996, as Wells's trial was about to begin, he confessed to his involvement in Donna's murder to investigators. However, he claimed that he and Riebe went to the convenience store, where Riebe robbed it and abducted Donna at gunpoint. Riebe then strangled Donna to death in the backseat. Afterwards, the two buried her remains.
Two days after his confession, Wells led investigators to Donna's remains, which were found on family property in DeFuniak Springs. Her remains were identified through dental records. Wells agreed to plead no contest to her murder in order to be spared from the death penalty. In 1998, Riebe pleaded no contest to first-degree murder; both were sentenced to life in prison.
Riebe later confessed to killing several women, including Pamela June Ray, missing from Panama City. However, he later recanted those confessions. Despite this, Pamela's family and some investigators believe that he is involved in her case as well as the other murders. He and Wells are also suspected in Deborah's disappearance.
- Police search grave site for area woman's body - June 12, 1993
- Experts sift Walton site for corpse - June 12, 1993
- Search for missing clerk suspended at Walton site - June 13, 1993
- Site Thought To Be Grave For Clerk Turns Up Empty - June 14, 1993
- Police come up empty in search for grave - June 14, 1993
- Wells’ attorney: Lawmen are after the wrong man - June 15, 1993
- Arrest likely 5 years after clerk vanished - March 7, 1995
- Santa Rosa grand jury indicts Wells - March 10, 1995
- Accused Killer Leads Police To Missing Woman's Body - July 16, 1996
- Unearthed remains - July 16, 1996
- Wells gets 2 life sentences - July 26, 1996
- Funeral ends 7-year nightmare - August 7, 1996
- 2nd man arrested in Donna Callahan slaying - May 2, 1997
- Could there have been two serial killers? - December 3, 2016
- How Many Did He Kill? The Mystery of Convicted Killer Mark Riebe - July 17, 2018
- Mark Riebe: Sins of the Father - July 28, 2019
- To Catch a Killer Episode
- William Wells and Mark Riebe at Florida Department of Corrections
- Donna Callahan on Find a Grave