Prime Minister John Key says the "tyres will be kicked" and tougher laws will be considered following the revelation former Tauranga man Tony Douglas Robertson was on an extended supervision order when he killed Auckland woman Blessie Gotingco.
The 28-year-old lost his fight for name suppression earlier this week, two months after he was found guilty on May 21 of raping and killing Mrs Gotingco on Auckland's North Shore.
Robertson was just 18 when he kidnapped and molested a girl in Tauranga in 2005, and was jailed in 2006 for eight years after being found guilty of seven charges, including indecently assaulting the girl and attempting to abduct two other children.
He was released in December 2013 and breached his conditions twice in a few weeks, and was deemed such a danger that he was to be monitored strictly for a decade, the maximum period of an extended supervision order.
Mr Key said the first thing "we would say is we have actually changed the law already so in terms of the law changes we've made, it's possible Tony Robertson would have had a PPO order [personal protection order] on him, therefore, been actually housed on what is essentially jail grounds."
Secondly, there were a number of reviews taking place, Mr Key said.
Corrections Minister Sam Lotu-Iiga told media on Wednesday he wanted the department's role to be reviewed although he was confident Corrections had done everything they could to monitor Robertson - and the Probation Service had reviewed itself.
"So I suspect we are not doubting that we will kick the tyres on that," Mr Key said.
Cabinet would have to consider whether there were other law changes to be contemplated, he said.
He wanted the Cabinet to consider the terms of reference on Monday.
"Ultimately, we will let it do its work but most people would sit there aghast with what has taken place and obviously feel deeply frustrated," Mr Key said.
"There is a balancing act here and a difficult one because there is a trade-off - whether you ever let people out into the community and if you do, under what conditions?"