Nicholas Prosper admitted murdering his mother and teenage siblings and had planned to target St Joseph’s Catholic primary school

A 19-year-old man who shot dead his mother and two younger siblings at their home in Luton was also plotting a shooting at his former primary school, according to police.

Nicholas Prosper admitted murdering Juliana Falcon, 48, Kyle Prosper, 16, and Giselle Prosper, 13, when he appeared at Luton crown court on Monday.