Wallis joined the
Metropolitan Police as a constable in 1976 after graduating from
Bristol University with a degree in Social Administration and Sociology. Prior to her service with Devon and Cornwall Constabulary, Wallis served with the Metropolitan Police Service for 18 years undertaking various roles including working at the Community Relations Policy Unit at
New Scotland Yard as a
chief inspector, with responsibility for developing policies on
domestic violence and racial attacks, as well as working as a
Detective Superintendent in South East London. She became the
deputy chief constable of
Sussex where Wallis was awarded the
Queen's Police Medal (QPM) in January 2002. At the time Wallis was short-listed to head the
Police Service of Northern Ireland (PSNI) in her native
Northern Ireland, but withdrew following her promotion to Devon and Cornwall. As chief constable of the Devon and Cornwall Constabulary, Wallis presided over the fourth largest reduction in crime out of all the police force areas of the UK in 2005–2006. Attempts at controlling overtime costs and the implementing labour study recommendations brought undue criticism on Chief Constable Wallis. Mass protest arose from the attempt to implement recommendations of a position regrading study. The evaluation was a re-grading exercise which was meant to ensure fair pay for all, but meant some faced pay cuts of up to £8,000< causing hundreds to protest. ==Retirement==