The suspect at times went off on tangents about cigarettes filled with fiberglass and seeing videos about psychotropic drugs.

Nearly a dozen people were injured in the attack before citizens -- including Derrick Perry, who was armed with a gun -- confronted the suspect, authorities said.

A 42-year-old man entered the Traverse City Walmart around 4:43 p.m. on Saturday and used a folding knife to stab five males and six females, according to the Grand Traverse County Sheriff's Office.