One of Phillip Cottrell's alleged killers glared at a man threateningly just moments before the Wellington journalist was beaten in an attack that shattered his skull.
Mr Cottrell, 43, who suffered from a brittle bone disease, was found unconscious in central Wellington about 5.35am on December 10 last year.
He died in hospital the next day.
Nicho Waipuka, 20, and Manuel Robinson, 18, are on trial for his murder in the High Court at Wellington.
The Crown says they attacked Mr Cottrell on Boulcott St as he walked home from his overnight shift as a bulletins editor at Radio New Zealand.
The jury today heard from a man who was allegedly threatened by Waipuka as he arrived at work on on Boulcott St about 5.35am, moments before the attack.
Dominion Post systems engineer Phillip Barton was leaving the car park opposite his work when he noticed two men in baseball caps walking up the street.
The taller man called out to him in a raised voice, saying: "What the f*** are you looking at?"
Mr Barton said it was meant "threateningly" but he did not take it in straight away.
As he crossed the street, Mr Barton said the taller man was "glancing back at me with a glare ... almost egging me on to say something".
He said the shorter man was walking on the other side of the street, hunched over and apparently disinterested.
Mr Barton said he went into work and did not hear about the attack until later in the day.
The jury has also been shown CCTV footage from several cameras on Boulcott St.
Less than half a minute separates the last footage of Mr Cottrell walking down the street at 5.35am, and footage of his two alleged killers running up the opposite side of the street.
The footage shows Robinson running ahead, with Waipuka a short distance behind. The two men are later seen almost side by side as a worker at the ANZ building arrives at work.
Mr Cottrell's sister Susan Hollows told the jury today she suffered from the same brittle bone condition as her brother.
She said her brother suffered some broken bones, but led a normal life otherwise.
His great passion was travelling, she said.
"He was always travelling somewhere - all over the world."
Under cross-examination, Ms Hollows told Robinson's counsel, Paul Paino, both her and her brother suffered from a mild form of the bone disease.
Ms Hollows said she had suffered about 10 fractures during her life, mostly during childhood and none resulting from any assaults.
She said they grew up in Hertfordshire in the United Kingdom, and Mr Cottrell emigrated to New Zealand in 2006.
She last saw him alive in Queenstown about eight months before his death. He was supposed to stay with Ms Hollows and her family in the South Island for Christmas, and was due to leave Wellington two days after he was killed.
Mr Cottrell's friend Andrew Bristol said his friend would call his condition "old lady bones".
The jury will tomorrow hear from two people who were allegedly threatened by the defendants earlier in the morning.
Nearly 70 witnesses will be called during the trial, which is set down for two weeks before Justice Forrest Miller and a jury of seven women and five men.