The first movie directed by Bertolucci, when he was 21 years old. The screenplay was written by Bertolucci, based on a story by Pier Paolo Pasolini.
A prostitute is found dead near a park. The movie follows the interrogation process of the people that had been around the park at the night of the assassination. The interviewees aren't motivated to tell the truth, given their own misgivings.
The story is told in a very poetic way, and Bertolucci had already published a prized book of poems when the movie was released.