One person was killed and three others were injured after a gunman opened fire inside a Costco on a busy Friday evening following an argument with a customer near the freezer section in the southern California town of Corona. The shooter, who was described by the Associated Press as having a Mohawk, was apprehended without incident and hospitalized due to an injury. AP also reports that one of the injured was an off-duty police officer from a neighboring precinct. Several customers were injured attempting to flee from the store after the emergency doors reportedly malfunctioned. “It’s not very fun when you’re scared and you’re running for your life and you’re trying to open a door that says ‘emergency’ and they don’t open,” a customer told CNN affiliate KTLA. “Everybody was freaking out. People were falling over each other.” Police have not named the gunman or the victim or announced whether the two knew each other.