Constable Condon was 29 years of age and had been stationed at Maranboy but was in Katherine for the annual race meeting. He had been having an evening meal with his wife, Marie, when he was alerted to a man terrorising people in a cafe in the main street with a .303 rifle. Condon was driven to the cafe by a taxi driver who had earlier been accosted by the offender.
As Condon was being driven down Katherine Terace he saw Terence Charles Stapleton walking near the cafe and got out and approached him. Stapleton shot Condon without hesitation when he was about 3 metres away. Condon fell but rose again only to have Stapleton shoot him a second time. Condon died from bullet wounds to the stomach and leg.
Sergeant Jim Mannion was then the Officer in Charge of the Katherine Police Station. As he arrived Stapleton fired at the truck and a bullet went through the driver’s door, grazing his leg. A search party could not locate Stapleton but he was arrested the following morning by Tom Hollow, a policeman from Pine Creek, while still in possession of the rifle.
Constable Bill Condon was buried in Katherine and a plaque was erected outside the police station (then located in Giles Street) inscribed "Killed in the execution of his duty". Constable Condon was posthumously awarded the King’s Police and Fire Service Medal for gallantry.
Stapleton was tried and the jury returned the verdict of guilty of murder and sentenced to death. An appeal was lodged by lawyer John Lyons on the basis that one of the jurors was not properly registered and a new trial was ordered. The jury at the second trial could not reach a verdict and a third trial was set. Stapleton was acquitted on the grounds of insanity and was held until the pleasure of the Governor General was known. He was sent to Pentridge prison in Victoria.
(copy modified from NT Police website)
A depiction of the shooting from a magazine called Eagle in 1962 - See the whole item.