Third-strike offenders have an average of 63 criminal convictions and 68 per cent of Kiwis approve of the hardline policy, according to a new survey.
Under the "Third Strikes" law, a person who has three warnings for serious violent, sexual or drugs offending can be sentenced to the maximum jail time without parole.
Justice Minister Andrew Little will take the controversial law, introduced in 2010, to the Cabinet next week to soften it, but a new survey has found the majority of New Zealanders support the law as it is.
The Sensible Sentencing Trust commissioned poll of 965 adults found 68 per cent of those who agreed to take part in the survey approved of the law, and 20 per cent did not. The rest were unsure or refused to answer.
National party supporters most approved of the law (78 per cent) followed by New Zealand First (66 per cent) Labour (63 per cent) and Green (48 per cent).
Sensible Sentencing Trust founder Garth McVicar said he did not expect the strong level of support for the law among Labour voters.
"Public safety has always been important to the New Zealand public, and this poll confirms support for Three Strikes is strong at 68 per cent overall support.
"Justice Minister Andrew Little's wholly ideological desire to repeal three strikes runs counter to not only the views of the general public, but a substantial proportion of his own party's voters," McVicar said.
"He risks blood on his hands when the inevitable re-offending by second and third-striker career criminals are back on the streets."
McVicar said the poll showed respondents had even greater support for three strikes when key data about the risk profile and criminal convictions records of the second and third-strike offenders was explained.
Second and third strikers made up only 1.35 per cent of the prison population, McVicar said – about 140 of the most serious violent or sexual offenders.
"These are some of the most prison-worthy offenders. If Andrew Little wants to free up prison space, it won't be achieved by repealing Three Strikes and letting out some of the highest risk offenders in New Zealand."
Third strikers had an average of 63 convictions by the time they progressed to the point, and second strikers had an average of 26.
McVicar said 88 per cent of second strikers were assessed as high risk of reoffending and 51 per cent of them committed their second strike while on bail, parole or subject to a sentence.
Home invasion and burglary were offences committed by 61 per cent of offenders on their final warning, or second strike.
At April 2018 there were 9632 people with a first strike, 273 on a second strike and four third strikers.
Only three people have been sentenced under "three strikes" and in all three cases the judges opted not to hand down the maximum sentence for the third strike.
Family First NZ said the independent nationwide poll showed the Coalition Government had no public mandate for scrapping the law, and that evidence proved it is having the desired effect.
"The law appears to be working as planned because there is a dramatic drop from the number of first strikes (9632) to second strikes (273), and then again to a third strike (4)," national director Bob McCoskrie said.
"Criminals aren't stupid. They are well aware of the law and its consequences. If the regime is scrapped, the Government is in danger of sending a message that we're not serious about the It's Not OK zero-tolerance message on family violence," he said.
Ministry of Justice figures provided in a December 2017 response under the Official Information Act analysed the number of offenders becoming second, third or fourth strikers in the five years after Three Strikes was passed, compared with the five years prior to 2010.
The figures showed a 34 per cent reduction in "strike" recidivism, McCoskrie said.
"This is the kind of result that should be welcomed, not repealed."
On Wednesday Little was at pains to point out that the changes being made were a "modest" package of measures.
"We're not doing wholesale reform until we get a good public debate going," he said.
Little said the existing option of home detention for sentences of under two years in prison was being used less by judges.
"The proposal that's going before the Cabinet is to give a bit of a statutory signal that we want more promotion of that as an alternative to prison."
The poll was conducted by Curia Market Research in late February and early March and was based on the responses of 965 respondents.
The poll has a margin of error of +/- 3.2 per cent.
Three Strikes by the numbers
• In 2016 there were 1446 first-strike offenders and 1538 in 2017;
• 57 second strikers in 2016 and 85 last year;
• 100 per cent of third strikers are assessed as high risk of reoffending;
• Third strikers have an average of 63 convictions on their record. Second strikers have 26 on average;
• 51 per cent on their second strike offend while on bail, parole or subject to a sentence;
• Since 2010 to April this year, there have been 9632 first strikers, 273 second strikers and 4 third strikers;
• 68 per cent of 965 people surveyed approve of the Three Strikes law.