According to Dennis Waterman on the DVD commentary to Abduction (1975), Stephanie Turner wanted Alison Carter to become a regular character and asked for a retainer fee. The producers did not agree to this and decided instead to kill off her character!
This is the first episode of The Sweeney written by Roger Marshall, he wrote another 7 episodes. The last one being Victims (1978). He previously wrote 2 episodes of Redcap (1964), starring John Thaw. He wrote 6 episodes of Mitch (1984), which he co-created, in which John Thaw had the starring role.
Every single episode of season two ranked in the top 10 most-watched programmes in the UK, with seven of the episodes reaching the top 2.
This particular instalment was the lowest-ranked of the season, rated as the joint 10th of the week, along with [Dinner for Three (1975)] and [Episode #8.3 (1975)].
All three had ratings of 7.05m according to the JICTAR system of measurement.
Patrick Troughton (Reg Crofts) previously appeared with Dennis Waterman in Scars of Dracula (1970). He also later appeared with John Thaw in The Dead of Jericho (1987). He was best known for playing the Second Doctor in Doctor Who (1963) from 1966-1969, 1972-1973, 1983 and 1985.