‘It’s a big area to explore’: Charles Williams on observing from ‘Inside’

In Charles Williams’ debut feature Inside, Cosmo Jarvis plays a notorious criminal who undergoes a spiritual reinvention while in prison, leading him to conduct sermons for his fellow inmates.

So convincing was his performance that, according to Williams, the UK actor managed to raise concerns among some of the real-life prison personnel brought on to work on the production.

“One of the guys who works at prisons every day said he’d thought I’d gone a bit far in casting too many inmates an...