Captain Homer Jackson carries a Smith & Wesson Mk II Hand Ejector. The series is set in 1889, however the revolver was not developed until 1915.
Inspector Abberline is portrayed as an elderly man in his fifties or sixties, while Inspector Reid is portrayed as a much younger man in his late thirties. In reality, Abberline was only three years older than Reid, and both men were in their forties at the time when this story is set.