Since becoming a Chicago police officer in 1992, Hansen has been named in at least 57 complaints, with allegations ranging from excessive force to minor personnel violations, according to Police Department records. Fewer than 1 percent of the officers who started that same year have more complaints, according to a Tribune analysis of the department records. He was suspended at least four times — an unusually high number of times, the analysis shows — but for no more than five days at a time.