Murder victim Richard Cater's family disappointed by sentence for 'raving marauder'

The "raving and violent marauder" who killed Richard Cater and seriously assaulted two of the 82-year-old's friends was sentenced in the ACT Supreme Court on Wednesday to 15 years in jail.

But Justice Michael Elkaim ordered that the 18-year-old, who was underage at the time of the incident and cannot be named, be released in 2027 under the terms of a partially suspended sentence.

The attack in question took place in March last year, when the killer consumed illicit substances including LSD that he had bought on the dark web for just $4 per tab.

He fell into a "drug-induced psychosis" and began roaming the streets near his home in the Gungahlin suburb of Palmerston.

Eventually, he happened upon a carload of elderly people, who were pulling up at Mr Cater's house after a dinner outing, and viciously attacked them.

The teenager bit and punched two of the victims, and pulled one of their heads forward so hard he fractured her spine.

Mr Cater ran to get a spade with which to defend his friends, but the teenager overpowered him and viciously stomped on his head as he lay prone in a gutter.

The 82-year-old stalwart of Canberra's watersports scene never regained consciousness after the completely random assault.

In sentencing on Wednesday, Justice Elkaim said finding the right balance had been very difficult.

"On the one hand there is an horrific series of events which include the murder of a good man much loved by family and friends, as well as serious acts of assault on two of his friends," the judge said.

"On the other hand there is a young man, with no criminal record, who did not intend to do what he did.

"I think he has shown remorse, is susceptible to rehabilitation and is entitled to the opportunity to eventually return to the community and to embark on a law-abiding path through life."

Justice Elkaim warned that anyone who took mind-altering drugs should be aware that they may undergo a "major personality change" as a result.

But he noted that the killer had previously used illicit drugs, including LSD, without "any psychotic reaction or any tendency to be violent".

"In my view there is no basis upon which I could conclude that [the teenager] knew, or even had regarded as a possibility, that his use of LSD would induce the psychosis in which he descended into a raving and violent marauder," the judge said.

"[This was] a state distant from anything he had experienced before, and far distant from what might be described as his normal personality."

Justice Elkaim also took into account a large number of victim impact statements read to the court by Mr Cater's family and friends earlier this week.

Noting that some of the statements had called for the killer to be jailed for life, the judge acknowledged that Mr Cater's family would "probably be disappointed in my decision".

"They should know that the law is not solely concerned with punishment, but is overwhelmingly concerned with justice," he said.

"Justice considers punishment, the rights of the victims and the concerns of the community, but also the rights of offenders and, in particular where young persons are involved, the entitlement to become a productive member of society through rehabilitation."

For those reasons, Justice Elkaim imposed the 15-year sentence and ordered that it be suspended after eight-and-a-half years. With time already served, the killer will walk free in September 2027.

Some members of Mr Cater's family sobbed in the public gallery as the sentence was pronounced.

Outside court, Mr Cater's son Mark said they were "most disappointed".

"No family should ever have to go through the tragedy that we have been through," he said.

"To know that the offender will be able to walk down the street our mother lives in sooner than we would like gives us no relief.

"Losing our father to a brutal, vicious, unprovoked crime is something my family should not have gone through and I would not wish this pain upon anyone.

"There is no closure for our family, as nothing can bring Dad back, but hopefully we can now focus on the good times we had with Dad and reminisce about the stories he used to tell us."