KEY POINTS:
Jurors in the tagger murder trial have retired to consider their verdict after being warned not to let public opinion sway them.
Businessman Bruce Emery has pleaded not guilty to murdering 15 year-old tagger Pihema Cameron on January 26 this year.
The Crown called 15 witnesses during the trial but Emery did not give evidence, or call witnesses in his defence.
Emery says Pihema "stepped into" the knife and he never thrust the knife into him, as has been alleged by a Crown witness.
Justice Hugh Williams this morning told jurors at the High Court in Auckland they must make their decision based only on the evidence they had heard.
In his summary of the case, Justice Williams said jurors had to "purge their emotions" and clinically study the facts.
"You have to be entirely un-influenced by prejudice or sympathy for anyone in the case."
He said jurors could not be influenced by public opinion.
To find Emery guilty of murder they had to be sure he was guilty "beyond reasonable doubt", Justice Williams said.
He then advised jurors on points of law relating to murder and manslaughter. Under New Zealand law, anyone charged with murder is automatically charged with manslaughter as well.
To convict him of murder the Crown had to have proven Emery meant to cause Pihema "bodily injury" and that he was likely to have caused his death and injury.
They also needed to have proven that Emery was reckless - that death could have happened as a consequence of his actions.
For the jury to believe Emery - who maintains he was defending himself - they had to be satisfied he felt there was an "imminent force to be resisted".
"Did he believe he was in danger of bodily harm or death and was defending himself... of that imminent threat," Justice Williams said.
But if they felt he was acting for other reasons, such as revenge, then self defence could not be considered reasonable for Emery to have used his knife.
Crown case
The Crown closed its case against Emery yesterday and, with the defence not calling any witnesses, both sides summed up their cases to the jury.
Prosecutor Aaron Perkins said Emery was not defending himself but using his anger to punish them for tagging his garage door.
"On a daily basis people do worse things than what Pihema Cameron did to this man. People are expected to show restraint, not take the law into their own hands."
Mr Perkins said Emery was "an angry man" who had a history of vandals tagging his property. "And he finally catches one."
"The combination of an angry man with a potentially lethal weapon. The outcome... is what we see here," he told the jury.
He asked them to consider the evidence of Pihema's friend, who has name suppression, and what Emery told police.
The friend said Emery had thrust his knife at Pihema while Emery claims the teen "stepped into" it.
Mr Perkins said Emery couldn't use self-defence as defence because that could only be legally used if that was the main motivation.
"He used the knife not in self-defence, but to vent his anger."
Defence
Emery's lawyer, Chris Comeskey, told the jury that what happened was not murder but self-defence.
The events that night happened quickly and Emery didn't have time to think, grabbing a knife when he should have grabbed a "non-lethal" weapon like a rubber hose.
"The accused could have gone home - but that doesn't make him a violent killer. He took a risk. If he's as angry as the Crown is saying, why wasn't it a frenzied attack?"
The knife that killed Pihema had a 14cm blade but a pathologist found it penetrated him only 5cm.
"It's more probable the deceased hasn't seen the knife and he's walked into it," Mr Comeskey said. "The pathologist said the knife went in 5cm, so it can't have been caused by a thrust."
He said if jurors had reasonable doubt whether Emery put the knife into the teen they had to acquit him.
