BANGKOK, June 24 (Reuters) - A former soldier fired gunshots in a coronavirus field hospital in Thailand on Thursday, killing a 54-year-old patient after earlier shooting dead a convenience store employee, police said. The suspect, 23, believed that the patients in the hospital in Pathum Thani near Bangkok were drug addicts and that he hated drug addicts, regional police chief Amphol Buarabporn told Reuters, after an initial investigation. The field hospital was once a drug rehabilitation centre and was reorganised to treat COVID-19 patients. Closed-circuit camera footage that circulated online showed the a man walking into a hospital in combat uniform and red beret brandishing a firearm. Hours earlier, the suspect shot and killed a convenience store employee in Bangkok over a dispute, Amphol said. The suspect was later arrested. Pictures of the scene at the field hospital showed broken glass in front of an area where patients were sat in their beds. In February last year, a soldier killed 29 people in a rare shooting spree at a Thai shopping mall while, which drew attention to treatment of junior military staff in Thailand.