Evidence destroyed, says Bain defence

Police have come in for a grilling over their handling of the Bain murder case, with David Bain's legal team saying evidence that could have cleared him was ignored or destroyed.

In sometimes heated proceedings in the High Court at Christchurch, Michael Reed, QC, spent most of day three of Bain's retrial scrutinising the police investigation into the death of Bain's parents and three siblings in Dunedin in June 1994.

He suggested to former detective senior sergeant James Doyle, who was second in charge of the original inquiry, that the police case had overlooked evidence against David's father, Robin, of a murder-suicide, such as claims of an incestuous relationship with daughter Laniet.

Mr Reed: What's happened is we have a one-sided investigation. David yes, Robin no. Do you see that?

Mr Doyle: No, I don't agree.

Mr Reed: You should have investigated Robin thoroughly, shouldn't you?

Mr Doyle: I believe we did investigate Robin thoroughly.

The court heard that Mr Doyle had authorised the destruction of samples of fingernail scrapings, skin and blood from the body of Robin Bain in 1995 after David was convicted.

Mr Reed put it to him that the samples of blood on Robin's hand, with the development in DNA technology, could have exonerated his client.

"The position today is that we will never know, and can never know, whether that was Stephen's blood or Laniet's blood. And short of some extraordinary explanation as to how that blood got there on the day, we know can't prove ... David's innocence, can we?"

Mr Reed asked if it would have been desirable for Robin's arms and hands to have been covered to preserve any gunshot residue.

Mr Doyle replied, "It would have been helpful, yes."