Murder accused David Benbow looked up "human body" on the internet the day before the Crown says he shot Michael McGrath and disposed of his body.
He also looked up a map of Lincoln, an area near Christchurch.
McGrath's body has never been found, despite thousands of hours of searching by police.
Benbow is on trial for allegedly murdering his childhood friend Michael McGrath in May 2017. The Crown alleges he killed him after McGrath started a relationship with Benbow's ex-partner of 17 years, Joanna Green.
At the High Court in Christchurch on Tuesday, the jury heard the evidence from digital forensic analyst, Brendon Sturgeon.
The search for the human body took Benbow to a healthline.com YouTube video showing the anatomy of a body. Sturgeon also gave evidence about Benbow turning his CCTV cameras off for a few days over the time McGrath went missing.
Sturgeon said when police examined the cameras, they were working as they should be.
Benbow's lawyer Kathy Basire told the court that alongside the searches Benbow made for "human body", there was also a large amount of "normal" searches for news articles, business contacts and other things.
The trial is in its third week. The jury has heard no body, murder weapon or forensic evidence has ever been found.
However, the Crown has said the layers of circumstantial evidence show Benbow killed McGrath.
The trial before Justice Eaton continues.
