Help in identifying an english movie

Need help in identifying a Hollywood movie. I dont have many details.

1. The movie is in 1980s and 90s.

2. In this movie a detective will be searching for hero.

3. He will find always a wrong person and the same person.

4. In one scene, he will chase the person in train and find the same wrong person.

5. I dont know if it matters or not, the detective, who searches is black.