Rachel Nickell was just 23 years old when she was stabbed to death while walking her dog on Wimbledon Common, in southwest London, with her toddler son.
Alex will revisit his mother’s killing in documentaryDeath On The Common: My Mother’s Murder, which airs on Channel 4 at 10pm on Tuesday.
She managed to draw out fantasies from Stagg that Britton interpreted as “violent”, but Stagg did not admit to killing Nickell.
While investigators were focusing all their attention on the wrong man, the real murderer was left free to kill again.