Lawrence later became the Head of English at Gunnersbury Boys' School in Brentford, Deputy Headmaster at St. Mark's R.C. School, Hounslow, and later was named Headmaster of the Dick Sheppard School, a Lambeth comprehensive school. In 1993, he was appointed headmaster of St. George's Roman Catholic School, Maida Vale, regarded as a troubled school with poor exam results. He improved the academic reputation of the school, but problems with violence continued – often occurring when pupils were targeted by people from outside the school.