Colleen Slemmer’s killers met at a training camp for troubled teenagers.
She was found with an inverted pentagram — a symbol associated with satanic groups — carved into her chest, sparking a panic in Knoxville in 1995.
Pike had accused Colleen of insulting her and trying to steal her boyfriend at the time, Tadaryl Shipp, who was 17.
Shipp remains in prison after being spared the death penalty under state law for his part in the attack because he was not yet a legal adult.
Two other residents at the camp later testified that Pike had boasted before and after the murder and showed them a piece of Colleen’s skull.
A year later, she was sentenced to death, while her boyfriend received a life sentence with the possibility of parole.
Colleen’s mother, May Martinez, drove 11 hours from Florida to attend the execution, she told People, externalbeside her husband Raul.
She said: “I wanted her [Pike] to remember who Colleen was and what she did and never forget that thought no matter where she goes.