The belief that "a knife equals a gun" when officers are confronted by an armed offender has been labelled a misconception by the Northern Territory police.
An NT police bulletin says the phrase could have come from past training but it has since been used "incorrectly, poorly explained or wrongfully interpreted".
The "knife equals a gun" credo also formed part of Constable Zachary Rolfe's defence at trial in February when he was acquitted of murder after he fatally shot Aboriginal teenager Kumanjayi Walker, who was armed with scissors.
"This broadcast is issued to address an identified erroneous belief or misconception amongst some members that knife equals gun in all circumstances when members are faced with a physical threat to themselves or others during their operational duties," the bulletin reads.
It says "operational training does not use this phrase as it bears no true resemblance" to an officer's "situational awareness, available tactical options and decision making when confronted with a weapon including an edged weapon".
Instead officers confronted with any weapon should "consider the principles of threat, time, distance and cover", the bulletin says.
"Adherence to these taught principles and added situational awareness in dynamic, unpredictable, and at times dangerous environments, will provide members the optimum response to maintaining everyone's safety and the ability in making a more informed use of force decision."
Lethal force should be used only as a last resort to protect life when an officer is faced with a life or death situation, it says.
NT police are also reminded the success of any operation will be judged primarily by the extent to which the use of force is avoided or minimised.
The use of the phrase at Const Rolfe's trial prompted the clarification, the bulletin says.
During the trial, Const Rolfe's barrister David Edwardson QC told the jury police training required Rolfe to draw his pistol and "incapacitate" when threatened by a person armed with a blade.
"He had been stabbed and his partner was locked in combat with an armed assailant with predisposition for violence," he said in February.
"He was taught, trained and drilled as a member of the NT police force that edged weapon equals gun.
"In other words, when an officer is confronted with an edged weapon, the appropriate response is to draw your weapon and be prepared to use it."
Detective Senior Sergeant Andrew Barram reviewed Const Rolfe's body-worn camera video after Mr Walker was fatally shot three times in 2019, as he resisted arrest in Yuendumu, 290km northwest of Alice Springs.
He told the Supreme Court the second and third shots were not reasonable because Const Rolfe fired them after Mr Walker had fallen to the ground with another officer on top of him.
The former officer in charge of the NT Police operational safety section also said Const Rolfe's first shot was justified "because he was confronted at close range with an edged weapon and stabbed with it".
"It is reasonable to believe his partner was also in danger."
In response to questions about the the bulletin, the NT police said it was "an internal broadcast relating to internal operational procedures and training".
