Man on the Roof (1976)
Detective Martin Beck investigates the grisly murder of a police Lieutenant in his hospital room, he soon realises the urgency of the case when it turns out the killer may hold a hatred for all policemen. police brutality, based on novel or book, mysterious man, sniper rifle, shooter, mental illness, police inspector, mysterious killer, revenge killing, active shooter, evading police, police murders, lone shooter
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