Anticipating the retirement of 20 to 25 police officers in the next few years, the Simi Valley Police Department is hiring younger officers to succeed them.The department began a hiring campaign about six months ago, Police Chief Mitch McCann said in an interview at Monday night's Simi Valley City Council meeting."We started studying and realizing we have many veteran officers, about 20 to 25, retiring over the next two, three years," he said.