WMG / The Lodger

Joe the cop is definitely The Avenger

We never see the real Avenger get caught at the end, and are just told that someone was caught red-handed. Meanwhile, who ... a) is weirdly possessive of Daisy; b) is prone to near-violent outbursts; c) openly compares himself to the killer; d) owns a scarf; and e) just happened to be out on Tuesday night, following Daisy on her date? Joe is deeply suspicious, and my headcanon is that he changed his routine after realizing people like The Lodger were onto his patterns.