Decades after Stephanie Jackson was gunned down in her own home, a “damning detail” could provide a clue to her killer. 

In the re-evaluation of Jackson’s case on Cold Justice, investigators focused on a crucial detail that might indicate Jackson’s murderer was someone familiar with her Florida residence, as previewed in the Oct. 11 episode titled “Deadly Message.”

Cold case investigator Nancy McNally clarified during a crime scene reconstruction that after Jackson was shot in her living room on the morning of Sept. 3, 1999, the assailant locked the house door using a “push button” mechanism on the handle.

That small detail led prosecutor Kelly Siegler to ask, “So, as he’s walking out, what kind of effort does he have to take to lock the door?” 

“He doesn’t have any effort at all,” McNally replied. “He just grabs the door and pulls it behind him.” 

Siegler raised the question of why a “real burglar” would lock the door after committing a murder, prompting homicide investigator Abbey Abbondandolo to propose his theory on the situation.

“I think it’s a habit,” he said. “You walk out, you always lock it.” 

It was a theory that McNally also felt made sense, given her own personal experience. 

“I don’t know about you guys, but the older house I lived in had just that lock type on the handle,” she explained, “and it just became a habit to push that button as I came out and shut the door.”

To investigators, it suggested that whoever killed the beloved mother and grandmother had been familiar with the property. 

“The most incriminating detail is that the killer locked the door on their way out,” Siegler mentioned to producers. “Does that seem like the act of an unknown intruder or thief? Not really. It seems more like a habit of someone who once lived here.”

This detail aligned with another aspect of the crime, as revealed in a separate preview. After killing Jackson, the perpetrator searched through several purses in the kitchen but chose only to take a driver’s license belonging to Jackson’s daughter, leaving behind the $187 in cash found in one wallet.

As Abbondandolo saw it, “That’s just sending a signal.”

Could Jackson’s killer have been sending a message to her daughter? 

To find out more about the heartbreaking case, watch Cold Justice Saturday, Oct. 11 at 8/7c on Oxygen.