New tests will be carried out next week on the gun used in the Bain family murders. The tests will by done by police with David Bain supporter Joe Karam and forensic scientists present.
Mr Karam announced yesterday police would be examining original fingerprints and conducting tests on the gun used in the murders in June 1994.
The development comes after claims in June that a photo of Robin Bain's body showed parallel markings on his thumb consistent with him having fired a gun on the morning of the killings - apparently proving his son's innocence.
''The Bain team, myself and forensic people will be in attendance and I'm very confident that the original fingerprints will show in fact that there are no cuts on [Robin] Bain's thumb and forefinger where the black marks were,'' Mr Karam said yesterday.
''If the fingerprints don't show cuts, police are going to be left in the position of saying what are these sooty black lines?''
A police spokesman said last night the decision to re-examine Robin Bain's fingerprints was made in June in response to TV3's 3rd Degree programme.
''What we said in June was an examination of the original photograph does not give any definitive indication of what the marks could be.
''There are other possibilities, including that they are minor cuts - we know for example, he was doing work on the roof.''
Police had never definitively said what they believed the marks were, the spokesman said.
''Anything at the moment is just a theory ... it might well be that we do all this testing and get no closer to a definitive explanation for them,'' the spokesman said.
He would not speculate what could happen should the tests prove they were gun marks on Robin Bain's fingers.
Earlier yesterday, Acting Assistant Commissioner (Investigations) Glenn Dunbier said police hoped the examination would provide ''greater clarity'' on what caused the marks.
''It also remains a real possibility that even after the originals have been examined there will still be no definite conclusion regarding the marks,'' he said.
Police announced last month they would be applying to the court for access to the originals of the fingerprints taken from Robin Bain, Mr Dunbier said.
''These will be examined thoroughly to see if they assist in determining the nature of the marks on Robin Bain's thumb.
''As part of this process, police will also carry out tests on the firearm and the magazines involved.
''The results will be subject to a full scientific analysis and it is likely to be several weeks before the outcome is known,'' Mr Dunbier said.
Mr Karam would not reveal when or where the tests would be held.
David Bain had been invited to attend but he would be busy at work, Mr Karam said.
The marks on Robin Bain's thumbs had apparently gone unnoticed for 19 years until 3rd Degree revealed that a gun expert had re-examined photos of Robin Bain's hands, and said the marks matched those made by gunpowder residue when loading the magazine of a rifle shortly after it had been fired.
At the time, Assistant Commissioner Malcolm Burgess said Robin Bain's fingerprints showed patches on the thumb, suggesting cuts from ''handyman'' work.
