Assistant Chief Constable Cann joined West Midlands Police in 1989 and initially worked in Birmingham City Centre as a local beat officer. Between then and 2002, he worked across the force in a variety of ranks and roles, before being promoted to Chief Superintendent in Wolverhampton in 2003.

After four very happy and successful years in Wolverhampton, he was promoted to Assistant Chief Constable in West Midlands Police in 2007. At that time his area of business was Citizen Focus; within that he was responsible for Criminal Justice and became Chair of the West Midlands LCJB. In 2009, he became the force lead for Crime with responsibility for CID, Public Protection and Intelligence.

ACC Cann leads nationally for ACPO on a number of areas, including: Electoral Malpractice, the National Ballistics Intelligence Service (NABIS), Victims & Witnesses and, more recently, Vulnerable Adults.