A detective has described frantic efforts to find two policemen who fled after they were discovered trying to install a tracking device.
A hearing is under way at Manukau District Court to decide if John Skinner and Iain Clegg will go to trial for the murder of Sergeant Don Wilkinson and the attempted murder of his colleague on 11 September 2008.
Detective Steven Hare was providing back-up on the night of the shooting as Mr Wilkinson and a colleague attempted to install the device at Mr Skinner's house.
Mr Hare says he heard clearly on the police radio that the officers were in danger, with someone telling them to get out of there after they had been discovered trying to install the device.
He says he was frustrated because the pair did not radio their location, nor were they at a pre-determined emergency meeting point.
Mr Hare became emotional as he described eventually finding Sergeant Wilkinson unresponsive in a driveway.
Earlier, a gun expert who sold Mr Skinner the air rifle police say was used to shoot the officers also gave evidence.
Ronald Young says it was an elite model with high pressure and a light trigger that would only be used by someone very serious about guns.