The families of three crime victims are exploring whether Department of Labour laws can be used to penalise government departments and staff who they say allowed their children's killers to be at large.
The family of murdered teenager Augustine Borrell wants those responsible for letting his killer out on bail and for monitoring him, to be prosecuted.
Haiden Davis was on bail for an aggravated robbery when he murdered the teenager.
The Sensible Sentencing Trust spokesperson Garth McVicar says there is a strong legal case.
He says the trust wants to hold accountable those people who put the conditions on Davis and who were responsible for ensuring those conditions were monitored and abided by.
Mr McVicar says a team of lawyers is working pro bono on the legal bid.
The mother of a woman killed by a disqualified driver also says she'll be asking the Department of Labour to prosecute government officials who failed to keep her daughter's killer off the road.
Debbie Ashton died when Jonathan Barclay's car hit hers in Nelson in 2006.
Barclay had earlier appeared in court on drink driving charges, but was treated as a first time offender because the judge wasn't told about his criminal history.
Debbie's mother Judy Ashton says private companies are punished under health and safety laws if they endanger anyone, and the same should apply to corrections or police officials.
And the family of Karl Kuchenbecker, who was murdered by Graeme Burton, is also writing to the Labour Department.