The Unexpected is Near (1971)

Crowded alleys of the evening park, music, laughter, festive fireworks. And the two are talking about murder or suicide, about the syringe found in the dead woman's hands, about the time when death occurred. These two are employees of the criminal investigation department. They will have to find criminals in a large, busy business city who stole, cheated, and, if necessary, did not stop at murder, removing unintended witnesses or unreliable accomplices from their path.