The actors improvise all the dialogue. They are given the outline of a story and individual scenes, but it is up to them how they decide to attack it.
Before starting the series, the actors were told absolutely nothing about their characters. As a result, Fay Ripley decorated Martha's desk with pictures of her own children.
There is a police adviser on set at all times.
A full, 60 minute episode takes just two days to film.
The series is produced at an extraordinary speed, with a full, 60 minute episode taking just two days to film.