Police carried out extensive surveillance on the man accused of killing a roadworker, and on the accused's family, during their investigation.
George Taiaroa, 67, was shot while operating a stop-go sign at a one-way bridge near Atiamuri in South Waikato on 19 March 2013.
Quinton Winders, 45, has been charged with murdering Mr Taiaroa, with the trial in the High Court in Rotorua opening yesterday.
A police detective told the court today that numerous production orders were made for the phone records of Mr Winders and members of his family, along with requests for bank, insurance, education and business information.
Detective Steven Lockett said he knew listening devices were placed in vehicles owned by the Winders family and in their homes and on their telephones.
But he said he had no knowledge of their friends' phones being bugged.
Accused didn't talk to victim at crash scene - witnesses
The Crown has said Mr Winders blamed Mr Taiaroa for a minor crash at a road construction site and that it was the catalyst for him returning to the scene a week later to kill him.
The court was told by witnesses today that Mr Taiaroa didn't talk to Mr Winders after the crash.
Mr Winders and his father were in a vehicle that backed into another vehicle after overshooting a stop sign.
One witness described seeing the Winders vehicle being waved back by Mr Taiaroa.
It reversed into the other vehicle.
Roadworkers told the jury people from both vehicles got out and exchanged details, but at no time did their colleague, Mr Taiaroa, engage with them.
The trial is before Justice Toogood and a jury of seven women and five men, and is set down for four weeks.