Many disgruntled Family Court litigants including a kangaroo shooter were not fully investigated by police trying to solve the 1980 murder of Justice David Opas, a Sydney trial has been told.
Elite and "prized" kangaroo shooters used one bullet to kill the animal in the head so the rest of the meat could be sold, solicitor Alan Conolly said on Thursday at the trial of his client Leonard Warwick.
The 73-year-old former firefighter has pleaded not guilty to four murders, including the shooting of Justice Opas, and 20 other offences relating to seven events which occurred between February 1980 and July 1985.
The Crown contends the Sydney murders and bombings are "inextricably linked" to drawn-out Family Court proceedings involving Warwick and his ex-wife, Andrew Blanchard, which ran from 1979 to 1986.
Justice Opas, who had predicted blood would be shed if more court security wasn't provided, was shot dead at his Sydney home when he answered the doorbell just as his family sat down to dinner.
His widow said he often commented on the "anger of these people that were before him".
Continuing the defence final address in the NSW Supreme Court on Thursday, Mr Conolly referred to police running sheets on suspects in the shooting.
"I think it is relevant to consider the sort of problems the judge was having with his court and a number of litigants."
The judge would have been very wary about opening his security-door to a litigant or a stranger, so he probably knew the person, Mr Conolly suggested.
One litigant had been jailed for contempt of court, had written to the Australian Senate complaining about Justice Opas and was described as quite unstable.
The man told police he didn't know where he had been that night.
"There are some things in life we remember if we are, as this man was, very angry at Mr Opas and the court," Mr Conolly said.
Another disgruntled litigant was a kangaroo shooter, who was said to have an unhealthy interest in firearms and known to be violent, unstable and a chronic liar.
The man's fingerprints were said to be "similar" to those found at the murder scene, Mr Conolly said.
A third man told police he was a hit man and Vietnam veteran with knowledge of explosive and knew who had killed Justice Opas.
"The police did not consider the possibility that a person wanted Justice Opas dead and hired a professional rather than doing it himself," he said.
"When one looks at the bombings, it screams out loud they were professionally done, they were contracts."
Another man phoned an associate before the shooting saying: "Justice will be done, watch the TV news tonight."
And another suspect, who was jailed by Justice Opas after abducting his children, threatened to kill his wife, adding "I will shoot him too".
Warwick is accused of the shooting murders of his brother-in-law Stephen Blanchard and Justice Opas, the bombing of Justice Richard Gee's home, of the Family Court building in Parramatta and of the home of Justice Ray Watson in which his wife, Pearl, was killed.
He also allegedly set off a bomb that ripped apart a Jehovah's Witnesses hall, killing Graham Wykes and injuring 13 people, part of the congregation offering support to his ex-wife.
The judge-alone trial continues before Justice Peter Garling.
Australian Associated Press