In September 2006, 16-year-old Cᴀssie Jo Stoddart, who was house-sitting for relatives in Pocatello, Idaho, was found stabbed to death inside the property. Investigators in the small town focused on the last three people who saw the popular teen alive: classmates Brian Draper and Torey Adamcik, along with her boyfriend, Matt Beckham. But the discovery of a buried videotape revealed a disturbing truth.

Stoddart’s case is being explored in the ABC News Studios true crime docuseries “The Scream Murder: A True Teen Horror Story.” It examines how Draper and Adamcik, both inspired by the 1996 film “Scream,” selected a victim and carried out the killing.

“In their minds, they were playing characters,” director Lisa Quijano Wolfinger told Fox News Digital. “In the videotape, you can hear them talk about how this was going to make them famous. When they committed this terrible crime, they imagined the FBI and others would see the tape and say, ‘Oh my gosh, these guys were such mastermind killers.’ They wanted notoriety. They wanted to be seen.”

But after killing their friend, investigators believe the boys were spooked.

“After the crime, they tried to burn the tape,” Wolfinger said. “They buried all of their evidence in a pit out in the canyon. So in the aftermath, they said to themselves, ‘Oh no, we should hide this.’ Ultimately, they didn’t want the tape found.”

Stoddart’s friends and classmates described her as a bubbly, well-liked teen with a close circle of friends. The community was blindsided and devastated by her sudden death.

“We talked to her high school friends and her art teacher, who knew her well and loved her very much,” Wolfinger said. “They all said the same thing — she was just Cᴀssie. She was kind and caring, with a big soul and big plans for her future.”

“I remember talking to the art teacher,” Wolfinger recalled. “He said, ‘She wasn’t the best artist. She was just Cᴀssie.’ To me, that was powerful because it was authentic. The love everyone had for her was genuine. Twenty years have pᴀssed, and it’s still not enough time — she was so loved.”

Draper initially presented himself as a concerned friend eager to take a polygraph test to clear his name. But just before the exam, he broke down and said he needed to speak with detectives.

Sitting beside his distraught parents, Draper told investigators that he and Adamcik went to the property where Stoddart was staying. He claimed they intended only to turn off the power and scare her while wearing masks. But then, according to Draper, Adamcik began stabbing Stoddart. Draper later led detectives to an area where they had buried the evidence. In the pit was a tape on which the boys chronicled their plot.

The recording showed the teens gleefully discussing plans for what they called their “first kill.” They referenced the movie “Scream,” saying they wanted to know what it felt like to take a life. The tape didn’t show the attack, but it captured Draper and Adamcik in Draper’s car soon afterward. They vividly described the adrenaline rush they felt and then talked about disposing of the evidence.

“This sense of raw excitement and glee in the aftermath of the crime was chilling to me,” Wolfinger said. “I found it fascinating that these two 16-year-old boys could do something like this without appearing traumatized at all.

“As a mother of teen boys, it was difficult to comprehend. I wanted to understand how that could happen — what was going on in their teenage brains that made them think it was OK or somehow justified?”