Serial killer John Cooper hid 500 sets of house keys in the cesspit at his home as mementoes, the Mirror can reveal. The 76-year-old monster is serving life for four murders in Pembrokeshire, west Wales.
Cooper shot siblings Helen and Richard Thomas at their manor house near Milford Haven in 1985. Four years later, he murdered husband and wife Peter and Gwenda Dixon on a coastal path near Pembroke.
Footage from his appearance on Bullseye in 1990 helped cold-case review officers nail him 21 years on, by matching his look on the gameshow to a sketch of the suspect.
And former Det Supt Steve Wilkins, who brought Cooper to justice, told The Mirror how he went from Peeping Tom and burglar to savage killer.
Read more on mirror.co.uk