Hollis undertook Voluntary Service Overseas in Ghana during his gap year before university.
[5] He ceased to belong to the Regular Army Reserve of Officers on 6 October 1982, thereby ending the period where he had been liable for call-up.
In 1994, he was appointed Assistant Chief Constable Crime and Operations of South Yorkshire Police.
On 31 July 2012, Hollis was appointed Honorary Colonel of the Humberside and South Yorkshire Army Cadet Force in succession to Lord Lingfield.
[10] Hollis studied for a Master of Arts degree in Modern History at Sheffield University.
[11] He was appointed Commander of the Order of the British Empire (CBE) 'for services to the Police' in the 2010 New Year Honours.