This is the chilling moment teen murderer Nicholas Prosper buys a gun in carpark the day before he went on to murder his family.
Prosper, 19, will on Wednesday learn how long he will spend in prison at a hearing at Luton Crown Court.
He has already admitted murdering his mother Juliana Falcon, 48, and siblings Giselle Prosper, 13, and Kyle Prosper, 16, at the flat the family shared in Luton, Bedfordshire, on September 13 last year.
The teenager was able to buy a shotgun and 100 cartridges from a legitimate dealer using a fake firearms licence that he made himself.
