Liam Reid, who was convicted of the rape and murder of deaf Christchurch woman Emma Agnew, has had his minimum non-parole period reduced to 23 years on appeal.
Reid was also convicted last year of raping and attempting to murder a university student in Dunedin, nine days after killing Ms Agnew in November 2007.
Reid was jailed for life with a minimum non-parole period of 26 years for the murder and sentenced to preventive detention for the rapes.
The Court of Appeal on Tuesday reduced his minimum non-parole period to 23 years.
However, an appeal against conviction was dismissed and the preventive detention sentence remains in place.
In making its decision, the Court of Appeal noted the necessity of "relativities" between cases.
It referred to convicted murderers such as William Bell and Graeme Burton who received terms of 30 and 26 years, respectively, but who both killed more than one person.
In noting these, the court found the minimum period handed down to Reid to be manifestly excessive.
Reid's lawyer David Bunce says his client is pleased with the reduction, but in practical terms he is still subject to an indeterminate prison sentence.
Mr Bunce says Reid was hoping to have his conviction overturned because the Crown did not present the defence with its DNA evidence until seven days before the trial. He says he has yet to talk to Reid about whether he intends to take his case further.
Ms Agnew's aunt Evelyn Pateman says she is surprised and disappointed by the Court of Appeal decision. She says though she still has faith in the justice system, Reid took one life and almost took a second.
The organisation Deaf Aoteoroa says the sentence reduction has angered some members of the deaf community.
