The Los Angeles police chief is retiring, he announced Friday, in an unexpected departure as the head of one of the nation’s largest law enforcement agencies. Chief Michel Moore’s tenure will end in February. “During my tenure, I know I’ve made mistakes and missteps,” Mr Moore said. Moore oversaw a police department struggling, like most others nationally, to recruit new officers in recent years. The Los Angeles Police Protective League, the union that represents rank-and-file officers, did not immediately have a comment on Moore’s retirement.