Gorilla video shown in murder trial

A murder trial has been shown footage of a person in a gorilla suit walking through a group people throwing balls around to illustrate an argument about inattention.

The footage, taken from a university study, was shown at the trial in the High Court at Auckland of Christopher Shadrock, who is accused of murdering Manukau businesswoman Joanne Wang in 2008.

Ms Wang, 39, received a head injury about 3.30pm on June 16, 2008 after being struck by a car driven by Shadrock, who allegedly snatched her handbag in the Manukau shopping mall carpark. She died the following day.

The crown alleges Shadrock, having snatched the handbag, tried to back away from a chasing Ms Wang but then chose to drive forward into her to get away when his path behind was blocked, thus killing her.

Shadrock's lawyer Chris Wilkinson-Smith say he is guilty of manslaughter and not murder. He said Shadrock argued he had no intention of injuring Ms Wang, that he was driving at no more than 25kmh when he hit Ms Wang, and say she was on the passenger's side of the car rather than in front when she fell.

Opening the case for Shadrock today, he also told jurors they would hear from a psychologist who said there was evidence people under stress didn't always see things that they would normally see.

That psychologist, Dr Joseph Sakdalan, told jurors that this could apply when people were focusing on a task in front of them, particularly when there was a lot of movement.

Shadrock's lawyers then showed a video that was shown to 199 observers who took part in a 1999 Harvard University study by Daniel Simons and Christopher Chabris.

Dr Sakdalan told jurors just before showing the video that the observers had been asked to count how many times the six people threw a ball to each other, but he did not tell jurors before playing the video that a person in a gorilla suit walked through the ball-throwing scene.

After showing the video, he said the observers were then asked how many people noticed an unusual event, such as a gorilla walking through the picture.

He said only 54 percent of those surveyed noticed the gorilla, indicating a substantial level of sustained inattention among a significant number of the viewers.

Two other videos from the same experiment were then shown - one a similar scene only with the people and the gorilla semi-transparent, and a second with a woman with an opened umbrella walking through the ball throwers.

He said subsequent studies into inattentional blindness replicated or supported these studies.

"Depending on where person's attention is during a moving event, it may be that substantial number of viewers fail to notice something unusual that appeared in the scene," Dr Sakdalan said.

Under cross-examination from crown lawyer Christine Gordon QC, Dr Sakdalan said the study did not show this phenomena would occur but simply that it may. He also said more of the observers noticed the woman in the umbrella than the gorilla.

Earlier, Mr Wilkinson-Smith told jurors that the speed Shadrock was travelling - no more than 25kmh - when he hit Ms Wang was one which would not normally have fatal consequences.

He said Shadrock was not shrinking away from the fact that he had done a terrible thing but that his only intention was to take her bag.

"He didn't think what he did was likely to kill. He didn't realise she was so badly injured until the 6pm news that night," Mr Wilkinson-Smith said.

"That's when he realised this was far more than just a bag snatching gone wrong."

Five other people - Maka Tuikolovatu, 21, Lionel Tekanawa, 23, Vila Lemanu, 25, Mateni Lynch, 20, and Terence Tere, 22, - all face charges of being an accessory after the fact to murder by trying to help Shadrock avoid apprehension.

Tuikolovatu is alleged to have hidden Ms Wang's handbag, while the other four are alleged to have set the white four wheel drive ablaze two days after the incident.

Shadrock, Tuikolovatu, Tekanawa and Lemanu also face charges of the theft of Ms Wang's handbag, which had about $4000 cash inside it.

The trial is into its fourth week.

- NZPA