Physics helps convict Gordon Wood of murder

25 November 2008

The murder of Caroline Byrne, a Sydney model, by her boyfriend Gordon Wood, and the controversy of Rene Rivkin's alleged involvement, has captivated the media for over 13 years, since her body was found in June 1995 at the foot of The Gap, in Watsons Bay, Sydney.

The Gap in Sydney's Watsons Bay, where Caroline Byrne's body was found in June 1995. The rocky ledge near the middle of the photo is the launch point at the top of the cliff used for Associate Professor Rod Cross' calculations.
The Gap in Sydney's Watsons Bay, where Caroline Byrne's body was found in June 1995. The rocky ledge near the middle of the photo is the launch point at the top of the cliff used for Associate Professor Rod Cross' calculations.

The case was finally brought to a close with Gordon Wood convicted of murder in November this year, after the jury agreed unanimously that there was enough evidence to show he was guilty.

Associate Professor Rodney Cross, from the School of Physics, provided key evidence for the trial that proved crucial to the murder conviction of Gordon Wood.

As an expert on the physics of sport and forensic physics, Associate Professor Cross worked on the case conducting tests to answer the question of whether the death of Caroline Byrne was the result of her jumping or being thrown off the cliff at The Gap.

"This is a really interesting case where physics was able to provide answers for one of Sydney's longest running murder cases. Caroline Byrne's body was found 11.8 metres out from the cliff, which was 29 metres above her final landing spot," said Associate Professor Cross.

"The only way her body could have landed so far out from the four metre wide rock platform was if she had a launch speed of at least 4.5 metres per second.

"We conducted trials using real women - police cadets at Goulburn Police College - jumping into a swimming pool to see how fast a launch speed they could achieve after a four metre run-up. None of them could get up to 4.5 metres per second by diving, although a few could reach that speed with a feet first jump," explained Associate Professor Cross.

"This sort of speed ruled out Caroline Byrne tripping or deliberately going over the edge or even being pushed by someone else. Only a person of elite athletic ability could reach this launch speed by running and then diving off the cliff edge."

Caroline Byrne also landed head first, which led Associate Professor Cross to investigate the sort of throwing motion which would have allowed a high enough launch speed to produce the calculated trajectory of her fall.

"Using men and women from the Goulburn Police College once again, we examined the different throwing styles possible with the men lifting and throwing the women. We trialed various underarm throws, overarm throws, spear throws and even two men swinging the woman's body over the edge," said Associate Professor Cross.

"The only method that could have resulted in the trajectory and head first landing of Caroline Byrne's body was a spear like throw, where the man's left hand was on her chest and his right hand on her crotch, with her body tilting upwards. In our swimming pool trials, we found this position allowed launch speeds of up to 4.8 metres per second.

"Given our results, it would have been practically impossible for Caroline Byrne to have jumped and land at the distance and in the way she did. She was thrown off the rock ledge at The Gap by a strong and fit person."

Gordon Wood weighed 80 kilograms and was 32 years old in 1995 when Caroline Byrne died, and could bench-press 100 kilograms, according to another employee at the gym he worked at. As a fitness instructor, Gordon Wood did regular weight training and would have been able to bench press about 1.25 times his bodyweight. Caroline Byrne weighed 57 kilograms.

The day before Caroline Byrne died, Gordon Wood and the famous Australian stockbroker, Rene Rivkin, had been called to give evidence to the Australian Securities Commission about insider trading in Offset Alpine shares. Another key witness in the murder case said that Caroline Byrne had been concerned about the relationship between Gordon Wood and Rene Rivkin. Rivkin was later found guilty of insider trading in relation to Qantas Airways shares, and committed suicide in 2005.

The Prosecutor told the court that Gordon Wood murdered Caroline Byrne because she had wanted to break up with him and he feared that she may divulge potentially damaging information about Rene Rivkin.

On 21 November 2008, Gordon Wood was found guilty of the murder of Caroline Byrne in the NSW Supreme Court.

So how did a physicist get involved in one of the most controversial and long running murder cases in Sydney?

"I was first approached by the police in 1997 about Caroline Byrne's case, when they were preparing for the coroner's inquest, but it was just a phone conversation. I was again approached by the police, six years later, in September 2003 about the case, and then spent two years on and off working with the police, measuring various jumping, diving and throwing speeds at swimming pools in Goulburn and Sydney. I also checked cliff and rock dimensions at The Gap that police had given me," said Associate Professor Cross.

"Early this year, I did a few more experiments, to measure throwing speeds of the Sydney University football team when they threw a punching bag. I then presented my evidence in court in October 2008."

Associate Professor Cross has written two books and published more than 40 journal articles on the physics of sport, including the article Fatal Falls from a Height: Two Case Leads, published in The Journal of Forensic Sciences, specifically dealing with the Byrne case and with the case of a woman who died when she fell off a balcony in the city.

Learn more about Associate Professor Cross' work in forensic physics at:

Contact: Katynna Gill

Phone: 02 9351 6997

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