The man accused of murdering five members of his immediate family faces various scenarios, depending on the outcome of jury deliberations.

David Bain has sat through a three-month retrial, which has ended nearly 15 years after his parents and three siblings were found fatally shot in their Dunedin home on June 20, 1994.

Bain was found guilty of the murders on June 21, 1995 and sentenced to life imprisonment with a non-parole period of 16 years.

After 13 years in jail, the Privy Council in London quashed his convictions and said he had been a victim of a "substantial miscarriage of justice".

Bain was freed on bail and in June 2007 the Solicitor-General, David Collins QC, ordered a retrial.

When the jury return to the courtroom at the High Court in Christchurch they will announce whether they've found him guilty, not guilty or cannot reach a unanimous decision - a hung jury.

Colin Withnall QC, one of the team of lawyers who worked on Bain's initial appeal, said the verdict would be "interesting".

If Bain was found guilty the judge would likely have to send him back behind bars to serve the remainder of his sentence, Mr Withnall told NZPA.

"The judge has no option but to impose five terms of life imprisonment, but he's got to be sentenced in accordance with the law as it stood in 1994."

That meant it was "unlikely" Bain would be given a longer non-parole period than he was initially sentenced to.

It also meant time Bain had already spent in custody would count towards time served for any new sentence.

"So really the practical effect would be that he would be eligible for parole again in another three years," Mr Withnall said.

If Bain is found not guilty it would mean he would be immediately released, but would not necessarily be compensated for his imprisonment.

"The government guidelines really don't provide for compensation unless effectively a person has proven that he's innocent.

"Although the Bill of Rights says you're presumed to be innocent until the contrary is proved, when it comes to paying money that presumption somehow doesn't apply."

The Minister of Justice and the Attorney-General would be responsible for making the decision for compensation, probably after taking independent advice on the matter, Mr Withnall said.

The last option is the jury could return without being able to come to a unanimous decision on Bain's guilt or innocence.

The usual practice after a hung jury would be to hold another retrial.

"In this case, I really think that would be oppressive.

"If after 15 years and three or four months of a trial a jury is unable to agree on a verdict - and I have to declare a certain amount of bias - I think it would be an appalling thing to start over again."