 Complete the following phrase:  The case increased the level of concern expressed about levels of violence involving school-age youths, and the safety of pupils and staff while in school, which were beginning to become public issues in the United Kingdom in the early 1990s. This followed the fatal stabbing of 12-year-old Nikki Conroy by a mentally ill intruder at her Middlesbrough school in March 1994. In March 1996, 16 young children and their teacher were 