One of the police officers shot in the Christchurch suburb of Linwood on Tuesday had a gun in his patrol car but decided he wouldn't need it, police have revealed.
Police have also said that the man accused of attempting to murder the two constables was tasered by a third officer after the shots were fired.
Canterbury District Commander Superintendent Dave Cliff says one of the three constables who attended the original callout on Tuesday was able to return to his car for his Taser and another had a firearm in his vehicle.
Within a few minutes of the police arriving, the dog handler was shot in the jaw, a constable was shot in the thigh and the police dog was shot dead.
The dog handler, who had access to the firearm, says he did not think the situation warranted removing the gun from his car.
And the constable who was able to taser the accused man only partially hit his target and could not prevent the shooting.
Two firearms were found at the house: a .308 rifle and a 22 gauge rifle.
The number of officers shot on duty in the last two years is now nine.
Christopher Smith, 34, appeared in the Christchurch District Court on Wednesday facing two charges of attempted murder.