Task: Question Answering
Input (English): Passage: Filmmaker Adam Green begins a documentary about artwork that features monsters.  Green is surprised when William Dekker, a retired police officer, contacts him and claims to have proof of the existence of monsters.  Green's wife reacts skeptically, but he reworks his documentary to focus on Dekker and his efforts to expose the monsters' underground home, which he calls "The Marrow". Green interviews Dekker at his house, who claims that he has seen many monsters and identified some of them through sketches. Dekker mentions his son once but diverts from the topic when Green inquires. The shooting crew of Green and his cameraman wait at the Marrow's entrance; a dug-up hole in the cemetery in the woods. On the first night they do not see anything although Dekker keeps claiming that he could see one of the monsters. 
Question: What does the person contacted by the police officer do for a living?
Output (English): Filmmaker.