Although the actual events occurred in Littlehampton, the filming did not take place there. Instead nearby Arundel and Worthing were used. Arundel was used for town and street events. All the seaside filming was carried out in Worthing.
Britain's first women police constables were employed in 1915; an important example of women showing they were capable of doing previously exclusive "men's work" during the First World War and not standing down afterwards.
In the movie Rose Gooding is Irish migrant. In real-life she was born in Lewes, Sussex, England. Jessie Buckley, who plays Rose, was born in Killarney, Ireland.
In the movie some characters (Gladys Moss, Bill and Judge Maccleston) are played respectively by the non-white actors and actresses Anjana Vasan, Malachi Kirby and Cyril Nri. In real-life Moss, Bill and Judge Maccleston were white.
One of the Police Constables who turns up to arrest Rose when they think she is at risk of fleeing prior to her trial is black. Actually this is conceivable (although unlikely due to low numbers at the time) as the first black policeman in England was appointed in 1837.