Boy, 13, held on suspicion of attempted murder after pupils aged 12 and 13 stabbed at Kingsbury high school Boy, 13, held on suspicion of attempted murder after pupils aged 12 and 13 stabbed at Kingsbury high school A police counter-terrorism unit was on Tuesday night leading the inquiry into the stabbing of two boys aged 13 and 12 at a school in north-west London. Police were called to Kingsbury high school in Brent on Tuesday afternoon after reports that a 13-year-old boy had been stabbed.