|“||I make a promise to watch after these boys. In many ways, they're my own.||”|
— Massey to Hotch
A former colonel, Massey later retired and became the leader of the Somerville Military Academy. He had been the superintendent for 30 years. Prior to the episode, the academy received a new student named Bailey Shelton, who was constantly bullied by most of the other students. Bailey's worst bully was a student named Tucker Calhoun, who would throw him into a laundry dryer and activate it with him inside. Massey was aware of the bullying, but since those who bullied Bailey were his favorites, he didn't bother to stop it, even taking pleasure from it. Later, another student was signed up to the academy, a troubled teenager named Josh Redding. Redding befriended Bailey and always put an effort into protecting him from Calhoun and presumably other bullies. One day, Bailey had enough of the constant bullying and committed suicide, hanging himself with his own bed-sheet. The tragedy left Bailey's father, Chris Shelton, heavily distraught, and Massey, not wanting to see the bullying be exposed, was able to convince him that Redding was responsible for causing Bailey's suicide, even though he pitifully gave Shelton his son's belongings just a minute ago. Though he believed Massey, Shelton read Bailey's diary and found out about the bullying that was allowed by Massey, enraging him and causing him to formulate a revenge scheme against both Massey and Redding.
When Massey scheduled a survival trip out in the nearby woods, his second in command, Lieutenant Shockley Tawes, allowed Redding to be a part of the trip even though he didn't have enough points that allowed him to be so. Tawes then texted the location of the camp to Shelton, who then found it and killed five of the six campers present (Calhoun and four of Bailey's bullies and Massey's favorites, also assaulting the former before killing him) as a message to Massey, making the deaths look like a mass suicide. Redding, who witnessed the entire thing, managed to escape, with Shelton in pursuit. When Tawes discovers the corpses, Massey calls in the BAU.
However, even though Redding was initially considered the prime suspect, Massey's decision to call in the BAU proves to be a mistake: when the team interrogates him, Tawes, and the other cadets, they find the link between Bailey, Redding, and Calhoun. When Redding killed Shelton in self-defense, using a Viet Cong-style trap, Massey realizes that it is time to put an end to everything. Just as the BAU realize that Shelton was the unsub and not Redding, Massey orders Tawes to find Josh and kill him before the team catches up to him. Tawes obliges and drives out into the forest, eventually finding Redding, but the BAU arrive, stop him, and rescue Redding. Massey and Tawes are later arrested for their involvement in the crimes in front of the cadets, and just as the police cruiser containing them drives away, Redding salutes them. It is safe to presume that both Massey and Tawes are incarcerated for what they did.
Massey's case may have been inspired by Russell Williams - Both were colonels in the armies of their respective countries who abused their power for criminal purposes.