A court verdict for a 48-year-old Whanganui man who killed his older brother has reopened debate about the defence of provocation.
David Bourke was found guilty of manslaughter on Tuesday, but acquitted of murder, after using the defence.
Provocation was abolished after it was controversially used by Dunedin academic Clayton Weatherston, who was convicted of killing his former girlfriend.
The Bourke killing preceded the change of law, so David Bourke was still able to use the defence.
Bourke's lawyer, Mike Antunovic, conceded during the trial that the shooting was deliberate, but said months of being implored by his brother to kill him caused Bourke suddenly to lose control.
Mr Antonovic says this shows the defence of provocation is still needed.
The Law Society is lobbying the Ministry of Justice to reinstate the defence of provocation, which it says should never have been removed.
It says there are circumstances in which even the most reasonable person can lose his or her self-control.