A 36-year-old man identified as Sean Steiner of Glendale, Arizona, was arrested after opening fire and running through traffic near the Trump National Golf Course in Rancho Palos Verdes, California. Authorities reported that Steiner carried a rifle painted green and purple with the inscription “Why so serious?”—a line famously associated with the Joker character from The Dark Knight—and additional phrases including “HA HA HA HA” and “Let’s put a smile on that face.”

Deputies discovered the weapon, which had an orange tip resembling a toy firearm, loaded with a round in the chamber and a full magazine inserted. Steiner admitted to firing one of the pistols near a landslide area to “get some anger out,” according to the Los Angeles Sheriff’s Lomita Station. Investigators also recovered two loaded handguns, high-capacity magazines, extra ammunition, a ballistic vest, and an AR-style pistol with an orange tip during the arrest on March 29.