father/son american serial killer duo (trying to find the film title)

I'm looking for the title of a film I watched maybe 10-15 years ago, about a father/son serial killer duo, where the opening scene quietly dollied horizontally through a countryside shopping strip (or maybe gas station?) where they had just killed a few people, and I think the son was still inside but then came out and entered the car with his father and drove off.

They were american caucasian, and... drove around while committing various murders, I remember the son wearing a white or some light coloured t-shirt.

While it's rather vague... would anybody happen to know this film?