DNA left on toothbrushes and a knife, and a single palm print, allowed police to put the killer of Auckland taxi driver Hiren Mohini behind bars following an unprecedented trial in China.
Xiao Zhen, 24, a kitchenhand, fled to China after fatally stabbing 39-year-old father of two Mr Mohini a number of times after a short, early morning taxi trip in January last year.
Xiao's trial was held in China - the first time a New Zealand murder case had been heard in a foreign court - and few details were revealed.
However, the Dominion Post, under the Official Information Act, obtained the police file given to Chinese authorities.
It showed police found in the taxi a blood-covered knife, snapped into several pieces. There were no useable prints on the knife but there was some DNA evidence.
A left palm print on the rear passenger window was the only print that linked Xiao to the scene.
A few days after the stabbing Xiao caught a flight to Shanghai. Two weeks later, a police search of his rundown Queen Street apartment found two green toothbrushes he had left behind. DNA testing linked them with the murder weapon.
Police also obtained images of Xiao at Auckland Airport and his departure card gave up a left palm print and a print of his right thumb.
Detective Senior Sergeant Hywel Jones said the investigation had been extremely challenging.
There were no eyewitnesses to the killing and the two men were strangers to each other, he said.
"The whole team worked long and hard and had to really pay meticulous attention to detail."
In August, Xiao pleaded guilty in a Shanghai court and was sentenced to 15 years in prison.
He told the court he had argued with Mr Mohini about Asian people working in New Zealand and had refused to pay the fare.
NZN