David Benbow denies killing childhood friend Michael McGrath. Photo / Iain McGregor
Former prison guard David Benbow is the only person with the “motive, the means and the opportunity” to murder his childhood friend Michael McGrath, the Crown alleges.
Benbow, 54, denies killing McGrath in the Christchurch suburb of Halswell in 2017.
He pleaded not guilty during a seven-week trial at the High Court in Christchurch earlier this year. No verdict was reached.
A retrial began at the High Court in Christchurch this week.
On Wednesday, Crown prosecutor Claire Boshier outlined the prosecution’s case against Benbow.
She began by saying Benbow told his counsellor he would like to “annihilate” McGrath 20 days before he disappeared.
After his disappearance, he allegedly told a friend, “I don’t give a f*** what happened to him - it just teaches you not to introduce your partner or wife to another man.”
The ‘annihilate’ comments were made after Benbow’s daughter told him she saw his ex-partner, Joanna Green, kissing McGrath.
Boshier said Benbow told a friend he was “very pissed off”, and another friend said he appeared “very angry and distressed”.
The Crown case was that Benbow planned to kill McGrath, and did so on May 22 at his home on Candy’s Rd, Halswell. They allege he then disposed of his body in a way that meant it had never been found.
The motive, the Crown said, arose out of Benbow learning of the relationship between Green and McGrath, who he had known since they were children.
Boshier told the jury the case was “circumstantial”, with no direct evidence. Exactly how McGrath was murdered was unknown because his body had never been found, the location of where his body was disposed of was also not known and there was no forensic evidence, such as McGrath’s blood or DNA. There was also no recovered murder weapon. She said Benbow did own a firearm, a .22-calibre rifle, which was missing.
While the Crown case consisted of many different strands of circumstantial evidence that may seem insignificant, when woven together, they became “much more important”, she said.
“When you put them all together, you find a series of otherwise inexplicable coincidences”, Boshier said.
“The only reasonable explanation for the disappearance of Michael McGrath is murder at the hands of David Benbow.”
“Mr Benbow is the only person who had the motive, the means and the opportunity to murder Mr McGrath.”
To prove the charge of murder, the Crown needed to prove he was dead, it was not an intentional disappearance and he had not committed suicide.
Boshier then ran the jury through a number of different strands of evidence the Crown case was built on.
She began with the intensity of the searches around the Halswell area for McGrath. She said if he had died in some other way that wasn’t murder by Benbow, he likely would’ve been found.
McGrath’s car and bike, which were his only methods of transport, were found at his home.
At the time of his disappearance, McGrath’s mental state meant he was at a “low risk” of suicide. He had depression in the past, with a pain disorder in his leg, but in May 2017 he was in a new relationship with Green, who he had fancied for years. He told Green they could be “soulmates”.
“His friends and family will tell you he had everything to live for,” Boshier said.
“He was making plans for the future.”
McGrath was also “highly reliable”, and if he said he would be somewhere, he would be, Boshier said.
Green told Benbow in February 2017 their relationship was over, and on March 3, 2017, she moved out with the help of McGrath and another friend.
Boshier said Benbow was “furious” about the break-up, and told Green’s sister he had “lost everything”.
After finishing a large deck for Benbow over the summer of 2016 and 2017, McGrath distanced himself from Benbow. There was only one phone call between the two men in March 2017.
However, a week before McGrath disappeared, Benbow turned up at his Checketts Ave home three times, first to ask for assistance in moving items around his section, then to invite him for dinner, and then on May 21, to make an appointment for McGrath to visit him at 9am on May 22 to move some railway sleepers.
Boshier said the Crown alleges moving the sleepers was a “ruse” to lure McGrath.
When police spoke to Benbow on May 23 at his home, he did not mention the sleepers. It wasn’t until the next day that he pointed them out on the lawn. When a police officer moved them the following day, there was no dead grass on the lawn.
Benbow had also been described as “obsessional” about CCTV cameras at his home. She said the cameras were turned off about a week before McGrath’s disappearance.
Boshier then ran the jury through means, motive and opportunity.
“Mr Benbow is the only person with all three.”
His firearm was missing, and his home on Candy’s Rd was in a secluded area with high hedges. His motive, she alleged, was not so much the break-up, but the knowledge Green was moving on with an old friend who was “soon stepping into his shoes in all manner of ways”.
She also said he had the opportunity, as the Crown said Benbow was the last person to see McGrath alive at 9am on May 22.
“Where means, motive and opportunity merged into murder.”
Boshier told the jury they would see CCTV footage the Crown believes shows McGrath driving his blue Subaru station wagon at 8.54am, taking his usual route to Benbow’s home.
Shortly after 9am, a worker from Lyttelton Port was driving home along Candy’s Rd when he said he noticed a blue Subaru station wagon on one side of the road and two men standing outside the driveway.
Boshier said Benbow used his cellphone “very little” on May 21, 22 and 23. The only time he used it on May 22 was to ring two close friends to ask if they had a jump pack for a car battery.
He claimed it was for his mum’s car. However, testing later showed her battery was only two years old and had a “low chance” of needing a jump start. Her car was also at her home.
McGrath’s car battery was seven years old and had to be kept on a trickle charger to work.
“The Crown says when Mr Benbow tried to start Mr McGrath’s car to return it to his house before anyone noticed he was missing, his car wouldn’t start.”
At various points on May 22, Benbow was seen wearing a baggy blue woolen jersey. However, the jersey had not been found.
Some blue fibres were found in the driver’s seat of McGrath’s car. It was not possible to test the fibres against the jersey.
Blue fibres were also seen on the driver’s seat of Benbow’s Toyota Camry. The tests said the fibres could not be excluded as coming from the same source.
Boshier said Benbow and McGrath knew each other almost their whole lives. Benbow had referred to McGrath’s mother as “mum” on occasion. However, after McGrath went missing, he never contacted her or offered to help with searches McGrath’s brother organised.
She also pointed to Benbow’s “extreme vagueness” in his interview with police about his movements and said he could not explain why his gun was missing.
Two months after McGrath went missing, police were granted a surveillance device warrant, meaning they were able to intercept his phone calls and text messages and place a covert tracking device on his car.
On August 4, 2017, after receiving advice from a geoforensic search specialist, police released a tactical media release detailing that an international expert had been working with police in the search for McGrath.
The release detailed that police had identified geographical areas of interest in the greater Christchurch area and that specialist search teams would be brought in to search those areas.
The following day, Benbow received a call from a friend. In the call, which was intercepted, the friend told Benbow about media coverage of the press release.
Benbow told his friend: “They’re leaving no stone unturned, so good.”
During the time police were tracking Benbow’s car, they logged a daily summary of his movements to identify any “unusual” trips.
Boshier said there were two trips that stood out, on August 6 and 7.
About 8pm on August 6, he drove to a rural address in Motukarara and stopped for more than two minutes.
On the following morning, he allegedly drove to the same area and stopped at two other spots.
They were the only times he went to that area in five months of surveillance, the Crown claimed.
Boshier posited whether Benbow was checking the area to see if police had gone there searching for the body.
“Whatever the reason, it was unusual and unrepeated behaviour of Mr Benbow … [which] came close in time to the tactical release.”
Police searched sections of the Halswell River and surrounding wetlands but found nothing, with Boshier likening it to finding a “needle in a haystack”.
Boshier said while the Crown alleged Benbow planned McGrath’s murder, “not everything went to plan”.
She said a break in someone’s usual pattern of life can “tell us a lot”. She then looked at Benbow’s activity between May 21 and 23, pointing to a spike in petrol usage, the distance he drove, and him not using his phone as often.
Police also found a diary at his home. Boshier said Benbow did not “habitually” keep a diary, and it was “something else out of character”.
Some entries in the diary were “obliterated” and could not be read. Some entries also appeared to be written at different times with different pens.
The trial, before Justice Jonathan Eaton, continues and is expected to call around 120 witnesses and last up to eight weeks.
Sam Sherwood is a Christchurch-based reporter who covers crime. He is a senior journalist who joined the Herald in 2022, and has worked as a journalist for 10 years.
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