On August 8, 1980, 16-year-oldJoyce McLainset out for an early evening jog in her hometown of East Millinocket, Maine, to get in shape for her upcoming high school soccer season.
When the popular cheerleader, honor student, and band member failed to return home, her concerned mother,Pam McLain, began driving around town, looking for Joyce.
Two days later, the teen’s partially-clad, bound body was found in a clearing behind the high school soccer field.
The discovery of Joyce’s remains sent Pam on an emotionally exhausting, 38-year journey to find the teen’s killer.
The decades-long mystery is examined in-depth on next Monday’s episode ofPeople Magazine Investigateson Investigation Discovery.
The episode, “Murder Among Friends,” airs on Dec. 10 at 10 p.m. ET. (An exclusive clip is shown above.)
Courtesy Pam McLain

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Pam McLain.AP Photo/Bangor Daily News, Denise Farwell

Her tireless effort never stopped until she found out what happened to her daughter on that warm summer evening in 1980.
“I wasn’t going to give up,” Pam tells PEOPLE.
What she found out shook Pam — and her quiet mill town — to the core.
People Magazine Investigates: Murder Among Friendsairs Monday, Dec. 10 at 10 p.m. ET on Investigation Discovery.
source: people.com