Police and legal experts say they know who murdered three Aboriginal children in Bowraville in the 1990s – a case plagued by accusations of police racism and incompetence and claims the justice system failed the victims' families.

Proponents of a retrial claimed a legal technicality was preventing important evidence from being heard in a court, which may have led to a conviction.

NSW Attorney-General Gabrielle Upton on Tuesday said the government would appoint Mr Wood to clarify the definition of the word "adduced" in double jeopardy laws by November this year.

Should the word's meaning be redefined, a retrial may be allowed and new evidence could be heard.

Colleen Walker-Craig, 16, Evelyn Greenup, 4, and Clinton Speedy-Duroux, 16, vanished from the same road in the northern NSW town over five months from September 1990.

Jay Hart, a white man who was close to the indigenous community, was tried and acquitted for Evelyn and Clinton's deaths. He was also a suspect in Colleen's death, however her body has never been found.

Supporters of a retrial said important leads were not explored by police and had not been heard by a court.

Police say subsequent investigations uncovered significant coincidences that link all three murders and tie them to Mr Hart, who has changed his name.

In 2012 Attorney-General Greg Smith refused to apply to the Court of Criminal Appeal for a new trial, which would lead to all three murders being heard together.

Among the reasons, he cited advice that an acquitted person can be retried only if there is fresh and compelling evidence which has not already been "adduced" in court.

Legal opinion is divided on whether adduced means "tendered" or "admitted". Some evidence the families believe warrants a retrial has previously been tendered in court, but not admitted.

Greens MP David Shoebridge said Mr Wood's task to clarify the word's meaning was "a very significant step forward towards a retrial" but the government had missed an opportunity to immediately reform the law.

While any future change to double jeopardy laws may potentially affect other cases, the review would not open the floodgates to retrials, he said.

Clinton's sister-in-law Leonie Duroux said she "couldn't be happier" with Mr Wood's appointment and she hoped it would lead to a retrial.

Ms Upton said the government acknowledged the pain the victims' families had experienced and there was no-one "more qualified or respected" to conduct the review than Mr Wood.

The government on Tuesday supported most recommendations of a parliamentary inquiry into the matter, including improved cultural awareness training for police.

Police initially claimed Evelyn and Colleen had "gone walkabout", and Detective Inspector Jubelin, who was heavily involved in the initial investigation, has said the families suffered racism and disrespect at the hands of authorities.