Corporal John Tanner was killed in action on 15 April 1945 at Lake Comacchio, Italy. The previous year on 20 March 1944 he was wounded (recovered) during operations in Italy. 
John Andrew Tanner, a City of London Police Constable, volunteered for the Commandos in 1942 and joined the 2nd Police Intake at the Commando Depot (Commando Basic Training Centre), Achnacarry. In 1939 he resided in the accommodation above Moor Lane Police Station, 3 Moor Lane, Barbican. Commemorated on the WW2 Memorial Plaque located at the City of London Police HQ, 37 Wood Street, City of London.

Sources
CWGC.
Casualty Lists / National Archives files WO417/74 and WO417/91.
The 1939 Register covering the City Of London.
Image of the Police Memorial heldby the IWM ref.86964