A murdered 12-year-old girl sent a secret signal to her friend the day she was kidnapped and later found murdered.
Jonelle Matthews was being dropped off at her home, which was empty at the time, by friend Deanna Ross.
Matthews, from Greeley, Colorado, disappeared that night with her body later found in a shallow grave.
Ms Ross told CBS News about that last night she was seen.
The two friends had been performing in a middle school Christmas concert on December 20, 1984, and afterwards Matthews asked for a lift home.
Matthew's dad was out of town and her mum was visiting her ill grandad.
Ms Ross said: "Jonelle needed a ride home … so she hopped in our truck and we took her home."
Once they arrived they devised a plan for Matthews to signal it was okay for Ms Ross and her dad to leave.
She continued: "My dad waited until he saw her flick on the light. That was our sign that she made it inside, and everything's fine."
The light was flicked on and off and Ross left.
Later that evening Matthew's dad called the police telling them his daughter was missing.
Footsteps were found in the snow near a window of the house where the girl often sat and a rake had been used to try and cover them up.
Her disappearance gained national attention and even then-President Ronald Reagan commented on it.
But no other clues emerged.
Until 2019, when the girl's body was found by excavators installing a pipe.
It was 15 miles from her home and DNA tests confirmed it was Jonelle Matthews' body.
A single bullet had been shot through her head.
In 2020, 71-year-old Steven Pankey was charged with her murder.
He had talked about her disappearance for years and had a history of erratic behevaiour around the case.
Pankey, who at one point was a Republican gubernatorial candidate, had even made a list of people of interest that had his own name on it.
People around him said that he had told them things that made them think he was involved.
When it came to trial he claimed he was just trying to get the limelight.
He said on the stand: "It was just me trying to be a big man, be in the case, OK? I had no knowledge.
"It began as a series of lies, and it got bigger and bigger over the years.
"One lie leads to another."
Prosecutors convinced the jurors Pankey was the killer and in 2022 he was convicted of murder and sentenced to a life term.
Anthony Viorst, Pankey's former attorney, maintained his innocence saying: "[T]here's no indication that he committed this murder, no indication that he had anything to do with burying the body.
"Mr Pankey loves the limelight … all of the statements that he has made about his culpability have been 'I didn't do it.'"
