Convicted murderer Scott Watson has been in prison since 1999. Photo: Pool / John Kirk-Anderson
Scott Watson's face "plastered" across television screens months before his arrest for the murders of Ben Smart and Olivia Hope may have influenced some eyewitness descriptions, the Court of Appeal has been told.
Ben Smart, 21, and Olivia Hope,17, were last seen climbing on board a stranger's yacht from a water taxi in the early hours of 1 January 1998 after a New Year's Eve party in the Marlborough Sounds. Their bodies have never been found.
Watson, now 52, was sentenced to life imprisonment with a minimum period non-parole period of 17 years.
Watson has always maintained his innocence. A Court of Appeal bid against his convictions was dismissed in 2000 and the Privy Council declined to grant Watson special leave to appeal in 2003.
In the Court of Appeal this week, the defence is arguing identification evidence was unreliable and its admission gave rise to a miscarriage of justice.
In court on Monday, Crown lawyer Stuart Baker questioned eyewitness identification evidence expert Dr Gary L Wells' reliance on the report on the evidence of water taxi passenger Hayden Morrissey, since he admitted only seeing the mystery yacht owner from behind.
He quoted from Morrissey's statement to police on 13 January: "He was really just a shadow, I couldn't see him".
Baker suggested it was "misleading" not to include that information in the report, and the experts had been "selective" with the evidence included.
Wells said however Morrissey's description of the mystery man was likely to be more reliable than that of water taxi driver Guy Wallace because, unlike Wallace, he had not been shown a photograph of Watson.
"So in that sense, he was a more pristine witness."
Secondly, the only physical description given by Morrissey was that the man had long hair, whereas photographs of Watson on that night showed he had short hair.
The report was based on "the totality" of the evaluation of witness statements, Wells continued, including Wallace's explicit rejection of Watson as the man he had seen.
"He says 'No bloody way was it this guy', we didn't put that in here either - but we're aware of it."
The report also found the later descriptions of the mystery man by Olivia Hope's sister, Amelia Hope, could have been influenced by photos of Watson she saw subsequently.
Wells noted Amelia Hope did not say anything about the man's hair until after Watson had been presented as a suspect on TVNZ, when she started talking about short hair and a receding hairline.
"Once you see the person plastered across TV or are shown a picture by law enforcement, if you are adding to your description, it's post-event information - not coming from memory of the critical event but from other sources."
The water taxi driver, Wallace, who later said he was mistaken in identifying Watson as the man in the water taxi with the young couple, was likely influenced by verbal or non-verbal cues from the police, he said.
"He's trusting that investigators are leading him down the right path and then he began to question it - but ended up coming around at time of trial."
That was not uncommon in similar cases, he said.
"Is that speculation? Yeah, that's speculation, but I don't know that you have better speculation than that."
