McWhirter is the Chief Constable of Suffolk Constabulary. He came to public prominence during the police 2006 Suffolk serial killer investigation in Ipswich in December 2006, one of the most prolific killers in recent British criminal history. Chief Constable is the title given to the commanding officer of every territorial police force in the United Kingdom except the two responsible for Greater London. ... Suffolk Constabulary is the police force covering Suffolk in East Anglia, England. ... In December 2006, the bodies of five murdered women were discovered at different locations near Ipswich in Suffolk, England. ...
He taught English and Drama in Winchester and joined Hampshire Constabulary in 1977. He served in all ranks up to Chief Superintendent in Hampshire working in cities and more rural areas with diverse populations and policing challenges.
McWhirter was in 1996 appointed Assistant Chief Constable (Operations) in the Wiltshire Constabulary ad here was responsible for all operational policing.
In 2000, he was appointed Deputy Chief Constable and he was appointed Chief Constable of Suffolk Constabulary in 2003. McWhirter is also the national spokesperson on Rural Policing issues on behalf of the Association of Chief Police Officers.