What true story is the lifetime movie a killer among us?

It's based on the 1985 murder of Michele "Missy" Avila by her best friends, Karen Severson and Laura Doyle in Arleta, California. The two girls were eventually sentenced to 15 to life for second-degree murder after a third girl, Eva Chirumbulo, who was there but supposedly didn't participate turned them in, three years after the crime. As far as I know they are both still in prison and have been denied parole several times as neither will take responsibility for the murder. The movie stays pretty true to the facts except for the name changes.