A mass murderer who served more than two decades in prison for fatally shooting five people in a Sydney public housing block in 1990 has been released back into the community on a supervision order.

Twenty five years ago this month, Paul Evers took the lives of five innocent neighbours, one of them his half-sister, over their taunts for being a 35-year-old "dole bludger".

After the shooting spree, Mr Evers went to a nearby milk bar, smoked a cigarette and was apprehended by police - who arrested him and took him into custody.

Mr Evers was previously released on parole seven years ago, but had his parole revoked after he was caught indecently assaulted a disabled woman and smoking cannabis.

Now that he has served his full 25-year sentence, authorities are unsure of what to do with the mass killer with untreatable schizophrenia.

Prior to his release, Mr Evers was earmarked for an 'Extended Supervision Order' by New South Wales Attorney General Gabrielle Upton.

"Way ahead of their release, we have the jail authorities working with the Department of Justice to identify serious risk offenders," Ms Upton told A Current Affair .

According to Sydney West Community Corrections director Michelle Micallef offenders on the register also receive extra attention from her department.

"We have six police officers, two psychologists, a legal team, an intelligence team and an electronic surveillance team who all work together to manage these offenders in the community," Ms Micallef said.

Like other offenders on extended supervision orders, Mr Evers received an ankle bracelet.

However, forensic psychiatrist Julian Parmegiana believes an ankle bracelet won't prevent another crime from being committed and that there are flaws in the system.

Dr Parmegiana cites the case of Peter Schneidas, who killed a prison officer while in jail, as a prime example.

"He was released in the community, with very close monitoring, and within a couple of months, he took his own life - in a place where he wasn't meant to be, with drugs he was not supposed to be taking," Dr Parmegiana said.

Victims of crime advocate Howard Brown says you can never absolutely guarantee that offenders will not re-offend.

Mr Brown cites two offenders under watch who recently cut their tags off.

"We've had them back in custody within 12 minutes of having cut their tags off," Mr Brown said.

Those two offenders were not alone in trying to remove themselves from the constant eye of the law.

"There are 54 offenders currently in New South Wales on those orders, there are 12 offenders currently in custody on breaches of these orders," Ms Micallef, of Sydney West Community Corrections, said.