How DNA evidence works
Authorities in Alabama were stumped by skeletal remains they could not identify.
In New Orleans, just two hours west down Interstate 10, law enforcement had an unsolved missing person’s case.
Although only 120 or so miles separated the two investigations, it would take more than 40 years for the right links fall into place, likely looping together the bones in Alabama and vanished New Orleans housewife Mary Ann Perez.
Due to persistence and a few lucky breaks, investigators now believe they can tie the March 1976 disappearance of Perez to a husband-and-wife serial killing couple who stalked women across the south in the 1970s, News 5 reported.
“It was actually a miracle,” Mobile County Sheriff’s Office Detective J.T. Thornton recently told the station.
On March 26, 1976, Perez went out with friends at a local bar outside of New Orleans. According to an episode of “Unsolved Mysteries,” the housewife left her teenage daughter Donna at home to watch her younger children.
“She told Donna that she would be calling to check on us,” Shannon Miller, Perez’s youngest child, told the program. “And Donna said she got a phone call from momma first, stating that she was OK and that she would be home shortly. And then Donna said she got a phone call from a woman by the name of Dorothy.”
The mystery woman on the other end of the line told Perez’s daughter her mother was having car trouble. The call immediately raised suspicion among the family — the vehicle was new, so it was not likely to break down. When Perez failed to come home the next morning, her car was found in the parking lot of a country-and-western bar. Three days later, Perez’s purse — weighed down with a brick — was found in Lake Pontchartrain, according to “Unsolved Mysteries.”
Perez was not found. She remained a missing person.
Eight months later, hunters were strolling through a cornfield near Grand Bay, Alabama, just over the Mississippi state line, when they discovered human bones. Clothes still wrapped the remains. The bones belonged to a woman, and distinguishing features stood out. “[I]t was mostly intact and there was also a partial dental plate the skull of the female indicated preexisting injuries from traffic collisions,” Thornton recently told News 5.
Investigators eventually shipped the remains to Oklahoma where the skull was used to reconstruct an image of the victim. But after the picture was released to the public, no one came forward to claim the bones or offer an explanation.
In the 1970s, information did not flow freely between law enforcement agencies - this was before internet databases or email alerts could quickly update departments in different states or regions about their caseloads. In 1976, no one linked the remains in Alabama with Mary Ann Perez’s disappearance.
But in 1980 investigators did begin to get a picture of her death.
David and Dorothy Courtney were a married pair of drifters who both pleaded guilty to murder in 1980 in Wichita The couple’s confession was chilling. They told investigators they had killed two others in Houston, and a woman in New Orleans, the Advocate reported. The Courtney’s account of New Orleans murdered echoed the facts surrounding Perez’s disappearance.
“When I went up to Kansas to interview David Courtney, he told me about the female he abducted in New Orleans,” New Orleans Police Detective Bob Lambert told “Unsolved Mysteries.” “He stated that he was driving down the highway and pulled in the parking lot of a country western bar.”
The woman was too drunk to drive home, Courtney claimed, so he pursued her to come back to the trailer he shared with his wife.
“He stated that this female fell asleep on a chair in the trailer and there was some sexual advancements by his wife, which woke this female up and she became disturbed and irate and upset about what was going on and then they agreed to give her a ride home at that time,” Lambert recalled.
While his wife drove the car, Courtney said he strangled the woman with a coat hanger in the back seat.
Despite the confession, law enforcement had a problem. The Courtneys pointed investigators to the final resting places of all their victims — all except the woman from New Orleans. According to the Advocate, the alleged killers only said they dumped the body either at the Louisana-Mississippi border or the Mississippi-Alabama border.
Authorities were left with a plausible theory for Perez’s disappearance, but no body — and therefore no criminal case. The Courtneys were never charged with Perez’s death. David Courtney is still serving a life sentence in Kansas. His wife died two decades ago.
In Alabama, investigators had the opposite problem: they had a body, but no plausible theory. According to News 5, it would take another 35 years for authorities in Alabama to uncover the connection.
Recently, Thornton, the detective, began digging into local cold cases, including the 1976 remains. A detective in Mississippi told Thornton about the Perez disappearance, and the Alabama investigator went to interview the missing woman’s family.
“They advised me that she had been in a traffic accident, Mary Ann Perez had, that she had a partial dental plate, and they presented me with the demographics of her and I thought that’s almost a perfect match,” Thornton told News 5.
But there was a new problem: the body had vanished again — no one knew where the remains were currently being kept. Only after a random encounter with another cold case investigator did Thornton finally catch his last needed break.
“The state attorney general’s office sent an investigator down here, who also works cold cases,” Thornton said. “So when he comes in he’s like ‘do you know anything about this case?” And I said I do and I’ve been hunting for the remains. And he’s like ‘we’ve been looking for the case that goes with the remains.’”
The bones were still in Oklahoma, where they had been shipped for the facial reconstruction.
They have since been transferred to Texas for DNA testing. Investigators say they believe the results will conclusively match the body to Perez.