Behind the Murder of JonBenét Ramsey, Featured on 'People Magazine Investigates'

Images of the petite 6-year-old pageant queen — a striking contrast to the horrific tragedy of her still-unsolved murder — have been seared into the public consciousness.

JonBenét Ramsey’s forever smiling visage belies her fate 20 years ago, a mystery that is the focus of the upcoming People Magazine Investigates episode “JonBenét: The Untold Truth,” which airs Monday night at 10 p.m. ET on Investigation Discovery.

Ahead of that broadcast, PEOPLE Senior Editor Alicia Dennis sat down on Friday’s People Now to preview the episode and talk about the ongoing search for answers.

“It was idyllic,” she says of the Ramsey family’s life before tragedy struck on the morning of December 26, 1996. “They were a wealthy family and JonBenét was a beauty queen. She participated in pageants like her mother had, and they were just a very close family. Everything looked really good.”

• For more on the case of the JonBenét Ramsey case, watch “JonBenét: The Untold Truth” on our 10-part true crime show, People Magazine Investigates, airing Monday night at 10 p.m. ET on Investigation Discovery.

That was upended when JonBenét’s beaten and strangled body was found in the basement of her family’s 6,800-sq.-ft. Tudor brick home in Boulder, Colorado, after her mother Patsy dialed 911 to report a ransom note and a possible kidnapping.

Two decades on, police have revealed no further progress toward identifying the killer of the little girl who was discovered with duct tape across her mouth, and a makeshift garrote tied around her neck that incorporated the broken handle of one of her mother’s paintbrushes.

WATCH: EXCLUSIVE clips of the People Magazine Investigates episode “JonBenét: The Untold Truth” on Investigation Discovery

Although investigators have voiced suspicions about those in the house — and family members were among those investigated — no criminal charges have been brought.

• Watch the People Magazine Investigates After Show, on the new People/Entertainment Weekly Network (PEN). Go to PEOPLE.com/PEN, or download the PEN app on Apple TV, Roku Players, Amazon Fire TV, Xumo, Chromecast, iOS and Android devices

Police continue to place their hopes for a resolution on DNA materials collected from the crime scene, which current Boulder District Attorney Stan Garnett said was “compromised.”

“DNA testing has improved over the years, and so authorities did tell us that testing is being done, says Dennis.

She adds, “So we have to wait and see.”