Palmu's suspicions about Kuurna are aroused due to his unusually proactive involvement in the murder case as well for delivering Kirsti's suicide note, which at first glance doesn't appear to concern him. After Kirsti's suicide attempt Kuurna is put under police watch. When he shines the light on a hanged mannequin on his window the police and Palmu first suspect he has killed himself. Kurt reveals himself to be the killer with his gruesome portrait of Palmu (where Palmu is depicted as Janus) where he accidentally painted the tipped pot over the gas-cooker, a detail only the murderer would have known.