Nicholas Prosper has been jailed for a minimum of 49 years for murdering his mum Juliana Falcon, sister Giselle Prosper and brother Kyle Prosper.

But the day could have been unimaginably more deadly.

The Luton teenager had planned to carry out the largest school shooting in UK history.

So what inspired him, what stopped him and what must be done to prevent such horror again?

ITV Anglia's Rosie Dowsing tells Lucy Watson what you need to know.