Richard Fleischer directed 20,000 Leagues Under the Sea, Fantastic Voyage and Doctor Dolittle for the family audience, and Compulsion, The Boston Strangler and 10 Rillington Place for nobody’s comfort. The second group is where the interest is.
The Boston Strangler used split screen extensively, not as a stylistic flourish but to convey a manhunt happening across a city at once. 10 Rillington Place is a quiet, methodical film about a serial killer that refuses any of the usual dramatisation.
He also made Soylent Green and Conan the Destroyer, which gives a sense of how wide a working studio career could be.