Filmed with part 2, in public locations for majority of exterior scenes. Included Woolwich, Thamesmead and parts of Erith Marshes. Due to the theme of the episode, it has kinship to one of the most controversial movie's made which was also filmed in same region = A Clockwork Orange (1971) (1971).
Central plot of this storyline involves a locally sensitive combination of key true-crime factors, where the production was filming that were altered to minimise any distress to families that reside in adjacent boroughs. Subsequent to prior media reported developments many of those events have been resolved by authorities.