Cressida Dick is replacing Bernard Hogan-Howe as the Metropolitan Police commissioner. She is the first woman to hold the post in its 200-year history, which has spurred hope that she will reform the Met in a period of uncertainty and strain. The budgetry perils the force faces are real: Hogan-Howe said recently that his successor’s biggest challenge would be ‘money’. But Dick has another problem too. She was the senior officer in charge during the 2005 operation in which Jean Charles de Menezes was killed. Firearms officers emptied eight rounds into the Brazilian electrician at Stockwell tube station after wrongly suspecting him to be a suicide bomber.