Advocates for battered women say a Law Commission review of whether victims of family violence who kill their abusive partners should be able to claim self-defence is long-overdue.
The commission is also considering whether a judge should impose a lesser penalty if an abused person is still convicted of murder.
Self-defence is argued when a person is under attack and defending their life.
But Law Commissioner Wayne Mapp said a person who has endured extreme violence may believe another attack will be fatal and may act despite not being in imminent danger.
"They have a deep belief that their life is in inevitable threat. This is how the Australian law works, but not how the New Zealand law works," he said.
Jill Proudfoot, director of client services at the anti-violence group Shine, said some abused women had been unfairly sent to prison.
"There's been some situations that have arisen that have been profoundly unjust on the person who committed the homicide because she had come to the stage that she was so terrified that she couldn't see another option," she said.
"Then their children not only lose their father to homicide, but their mother to imprisonment. But the intention of the woman was to protect her children, rather than to further harm them."
Mrs Proudfoot said in some cases women who kill had reached out for help and had not received it.
She said Shine did not think violence was acceptable, but New Zealand needed to have a good look at why women were driven to kill.
Noel Sainsbury, vice-president of the Criminal Bar Association, said in cases of severe abuse, victims should be able to claim limited culpability.
But he said the Law Commision should look more widely at the cupability of other groups also driven to acts of violence.
"What about those who are mentally ill, but not legally insane? We deal with that as a sentencing issue. What about those who are abused outside the domestic relationship?
"If we are going to look at this, look at this across the board, rather than politically acceptable forms of limited culpability," he said.
The Law Commission was also looking at non-fatal strangulation as a separate crime.
It will report back to the Minister of Justice in March next year.