The 4 deaths in this episode bring the total for the series to date to 29.
- Corn Exchange, Wallingford, Oxfordshire (Causton Theatre)
- Dorney Court, Dorney, Buckinghamshire (Fox and Goose Hotel)
- Halton House, Wendover, Buckinghamshire (Monarch Tobacco headquarters)
- Halton, Wendover, Buckinghamshire
- Hambleden Mill, Hambleden, Buckinghamshire
- Stoke Park Club, Stoke Poges, Buckinghamshire
- Stoke Poges, Buckinghamshire
- Turville, Buckinghamshire
- Wallingford, Oxfordshire (Causton)
The murder victims:
1. Carla Constanza - strangled
2. Anna Santarosa - run over and injected with liquid nicotine
3. Dr Aycott - arson
4. Leonard Pike - throat cut
The old mill seen at the end of Strangler's Wood is Hambleden Mill, Hambleden, Buckinghamshire.
The scene in which Leonard Pike is killed in a bathroom is an obvious reference to famous shower scene in Hitchcock's movie "Psycho".
Dan Peterson, the medical examiner states that one can extract lethal dose of nicotine from "half a pack of cigarettes". However, lethal dose of nicotine for adult human is about 50 mg and even strong cigarettes usually contain no more than 1 mg of this substance.
- The dead body of hotelier Leonard Pike still breathing after being stabbed several times, especially in the neck.
- A body lying, uncovered, in the woods for a week would show signs of decomposition. The body shown was in remarkably good condition.
- The newspaper shows a photograph of the "unknown" murder victim dressed and obviously alive, although her body was found nude and without any identification. How did they get the photo if they didn't know who she was?
- Troy speaks to the au pair in Spanish. Later on it is said that the au pair understood a message in Portuguese because it was "her language." Spanish is not the same language as Portuguese, obviously.