Nicholas Prosper, 19, pleads guilty to murdering Juliana Falcon, 48, Giselle Prosper, 13, and Kyle Prosper, 16

A teenager who shot dead his mother and two younger siblings at their flat in Luton was also plotting a school shooting, according to police.

Nicholas Prosper, 19, admitted shooting dead his mother, Juliana Falcon, 48, Kyle Prosper, 16, and Giselle Prosper, 13, when he appeared at Luton crown court on Monday.