How a principal protected his students from a knifeman.

On March 27, last year, Matthew Lennox told staff members he had a pistol when he entered Slough’s St. Joseph’s Catholic High School, a huge knife tucked into his waistband. The head teacher who confronted him a year later has now spoken out.

A staff member saw a young man who didn’t appear like the other sixth-formers when he passed through the school gates shortly after 11:00. The individual was peering out of an office window.