Harris wanted to join the United States Marine Corps, but his application was rejected shortly before the shootings because he was taking the drug fluvoxamine, an SSRI antidepressant, which he was required to take as part of court-ordered anger management therapy.
Harris a vrut să se alăture Corpului Maritim al Statelor Unite, dar cererea sa a fost respinsă cu puțin timp înainte de împușcături, deoarece el lua medicamentul "Luvox" (fluvoxamină), un antidepresiv "SSRI", pe care trebuia să îl ia în cadrul terapiei de gestionare a mâniei.