Bullitt (1968)

This film is the vanguard of a new Hollywood police and bandit film directed by Peter Yates, a famous commercial film director. This film depicts a loyal San Francisco detective assigned to protect a mafia member who will testify in court. The evidence provided by the witness contributed greatly to the destruction of important mafia organizations, but the man was assassinated. The detective felt that the situation was suspicious and went all out to track down the murderer.