Guthrie, a New Zealand Police sergeant in the Armed Offenders Squad, was sole duty officer at Port Chalmers police station on 13 November 1990 when he received a report that a man was firing a weapon indiscriminately at Aramoana, a small seaside township 8 km north-east of Port Chalmers.

Guthrie immediately went to the town and liaised with Police Constable Russell Anderson, who had arrived separately with the fire brigade.

In all, the gunman killed thirteen people and seriously wounded two, before Special Tactics Group police shot him dead the next day.

The service and final blessing were given by the Anglican Bishop of Dunedin, the Rt Rev Dr Penny Jamieson, and he received the naval honour of the piping the side, followed by a private cremation.

[2] The citation for Guthrie's George Cross was published in a supplement to the London Gazette on 18 February 1992, reading:[3] On 13th November 1990 at the seaside resort of Aramoana, located on the outskirts of Dunedin, a young man ran amok with a firearm and massacred twelve people before being fatally shot by Police the next day.

Sergeant Guthrie took immediate command of the situation, armed the Constable with a privately owned rifle and the pair reconnoitred the village.

With limited resources available to him and impending darkness Sergeant Guthrie had the task of locating and containing the crazed gunman, dealing with the wounded and preventing further loss of life.

His actions in placing himself in danger to protect his staff and members of the public at the cost of his own life were selfless acts of heroism.