Some family members of murder and rape victims have told Radio New Zealand they live in fear that the offenders could seek retribution or contact if released from prison.
Last week the two daughters of a man who killed their mother with a hammer said they believed their father would track them down, once he got out of jail.
Martin Schofield was sentenced to life in prison and must serve 11-years for killing his partner, Katrina Drummond, in their Taupo home in April this year.
Schofield's daughters are not alone - there are many other people who share similar fears.
One woman said her daughter was sexually abused from age five until 13 and her abuser, David Frethey, was sentenced to six years in jail in 2011.
She said the former Hawke's Bay jockey had been granted parole and would be released at the end of this month.
The woman said while he would be under strict parole conditions, his past behaviour did not give her family much faith in the system, and she feared he would come back to torment her daughter.
"He's threatened us, stalked us while being on bail, he's come into my work, we've had letters and also some from inside prison as well.
"He's got 13 conditions on his release and one of them is that he'll be GPS-ed but with all the GPS stuff going on at the moment, I don't hold much luck on that."
The woman said her daughter had slowly put her life back together but the family home had alarms that connected straight to the police, and it felt like they were living a double life.
"Because you can't be yourself because you're forever looking over your shoulder wondering what's coming next and who's around you.
"Your sensors are wired quite well and you're forever looking around thinking is it that person, you're just constantly on high alert all the time, you just can't relax," she said.
The two men who brutally murdered Margaret Jamieson's parents in 1994 in one of the country's first home invasion cases are still in prison.
But that has not stopped Margaret and her husband Jock from having to attend more than 20 parole hearings for the killers, Leith Ray and Gresham Marsh.
For them too, the nightmare is never really over, and Jock Jamieson said they have repeatedly had to outline to the parole board why these men should remain in prison.
But he said the pair would probably walk free some day and there was always a chance these men may want retribution.
"They do know what we have said about them and the reasons why we think they should stay in prison. So they've certainly got the message that we don't want them out.
"Whether or not they have some resentment over that, [it's] hard to say, but if they have some resentment then we have to be wary," he said.
In 2000, while hitch-hiking, 20-year-old Lisa Blakie was murdered by Timothy Taylor who has been in prison since 2002.
Lisa's father, Doug Blakie, said Taylor has had three parole hearings, and he even met his daughter's killer in prison.
The case is far from over for Mr Blakie.
"Yes he was convicted of my daughter's murder and yes I despise him for his participation.
"But I've always said there were others involved in Lisa's murder, and it's been my aim in life since Lisa's murder to get true justice. I've got partial justice but I haven't got true justice, I believe," he said.
As if serving his own life sentence, Mr Blakie said he would never give up fighting for the full truth about his daughter's murder.