Michael Griffey’s Bizarre Murder Mystery


Ahern Road, Pakenham

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Photo: Shows the location of Michael’s Pakenham home.

Michael Griffey:

Michael Griffey was a 45-year-old wealthy business man who, at the time of his death, was living in a lavish $500,000 Pakenham home complete with tennis courts and swimming pool with his treasured Monaro parked in the garage. By friends he was described as a ‘go-getter’, and the community remembers him as a popular, caring man as he was a generous supporter of district clubs and charities, particularly those involving junior sports. Michael had been a coach for the Pakenham under-12’s cricket side and had often picked the team up in one of his limousines.

Michael was living with his children and estranged wife but was rumoured to be having multiple affairs and was financially supporting other women – he had paid a deposit on a Pakenham home for one woman, and was paying the mortgage/rent of another woman in Canberra.

Michael Griffey was reported missing almost a week before the gruesome discovery was made. 

Mysterious Murder:

Michael was found covered by a bed sheet and tarpaulin, in the garage at 9:45pm on 2 January 2005 by his estranged wife and daughter. The daughter, aged 15, claimed to have first noticed a smell, ‘like something rotting’ before seeing the blankets and the blood. The realisation hit her when she saw her dad’s sunglasses ‘hanging out the end’ closest to her, and ‘a bit of his thongs’. During the call to 000 the estranged wife was too hysterical and the phone had to be passed to the daughter – police describe the family at the scene as ‘devastated’.

When examined there were three fatal lacerations found on the head, and one defence type injury to the wrist. The injuries had been sustained from an unknown blunt instrument, and a wood splitter found in the house was one of the items seized during investigations. Through decomposition analysis the attack and killing was determined have occurred between 2pm-3pm on the 29 December, and the body had lain undiscovered underneath the bed sheet and tarpaulin for four days.

Michael’s wallet and mobile phone had been stolen, along two pages from Michael’s diary and with $1000 from a safe to which only three people had the combination. There were 2 life insurance policies valued at $1.54million, to which his estranged wife was the beneficiary.

Photo of house

Photo: Ariel photograph of Griffey’s $500,000 property in Pakenham.

Interestingly, the family had hosted a New Year’s party on the property just days prior to the discovery,  with friends, family and members of the community, all seemingly unaware of the body decomposing just metres away from them.

Time to Meet the Family: 

Diane Griffey after charges dropped

Photo: Diane Griffey, estranged wife of Michael Griffey.

Diane Griffey: Diane met Michael in Ballarat and they had moved to Melbourne and began operating their company D&M Plaster Transport together. They later branched out for a few years, running their Metro & Pakenham Limousine Service. They eventually separated, but they lived together with their three children and maintained a sexual relationship up until the time of  the murder. Diane knew about Michael’s mistress, and rumours of other affairs, but was seemingly unphased – even calling the mistress to engage in amicable conversation about the man that they both loved. Despite their marital problems during a recent health scare he had told Diane that she was the ‘only woman he truly loved’, and friends said that Michael would never say a bad word about her. 

Michael had however, complained to his friends about his wife’s financial dealings – with her recently writing a number of cheques that had bounced. The transport company they owned was facing financial hardship in the months leading up to his death, and in 2008 it was revealed that the company had owed $1million to the tax office, and over $100,000 to other creditors.

Cassandra Griffey

Photo: Cassie Griffey, one of Michael’s daughters.

Cassandra Griffey: One of Michael’s daughters, Cassie, was described as having a good relationship with her father prior to the murder and was described as being ‘daddy’s little girl’. 

Kenny Griffey: Michael and Diane’s son was a race-car driver at the time of Michael’s murder.

Michael and Sister

Photo: Michael Griffey photographed with sister Katrina Fitzpatrick.

Katrina Fitzpatrick: Katrina was Michael’s sister. When she had last seen Michael, just a month prior to his death, he had given her a necklace, told her that he loved her and begun to cry. Katrina believes that she knows who killed Michael, and is frustrated by the lack of evidence. 

Gillian Gould: Gillian was Michael’s mistress of 5 years, and had known the couple for a long time. Gillian stated that Michael did not trust his wife due to the bouncing cheques. He was embarrassed and distressed as people that he knew at the bank, and through racing cars were calling him up about the cheques. This was confirmed by a friend of Michael’s that said that they’d discussed a $5000 cheque that has bounced prior to New Years.


Kenny Griffey was briefly investigated, but denied the allegations and with no evidence implicating the son the investigations into him were dropped.

In 2007, Michael’s estranged wife Diane was charged with the murder. There were three key pieces of evidence against her: 1) Diane had described to the police the striped bed sheet by which the body was covered. The bed sheet was however, hidden completely by the tarpaulin that was laid on top, and having claimed that she had not touched the body it would have been impossible for her to know this, 2) Michael is said to have texted Diane twice on the day of his murder, and 3) Diane is the beneficiary of Michael’s will, and will gain approximately $1.54million from his murder. Michael’s mistress claims that there was a more recent will made, and the two had plan to wed soon, but evidence of this was never found.

It was during the preliminary hearings of the trial against Diane Griffey when the daughter, Cassandra confessed to the murder. The trial was adjourned while police investigated the confession, but soon after the police said the confession was not credible as it was found that her version of events did not match key evidence in the crime. No charges were ever made against Cassie.

Diane pleaded not guilty to murdering her estranged husband, and denied police allegations that she had planned to benefit from the $1.54million life insurance policy. The case was dropped by the prosecution in 2008 as there was not enough evidence to implicate her, and it was ‘far from being a strong circumstantial case’.

Although police said that there were ‘several people of interest’ no one has ever been charged, and there have been no new investigations for almost 10 years. 

Theories & Speculation:

 Michael Griffey

Photo: Murder victim Michael Griffey.

A Melbourne friend of Michael’s stated that he would ‘like to know what he’d done to deserve that’, and it seems the only two options that we are left with in this case is love or money.

The daughter confessing to the murder seems to be a red herring, confessing only to protect an individual – either her mother, or the killer if they are not one in the same. The daughter could possibly hold key information about the death of her father, but is an unlikely suspect.

The missing pages from the diary and the money stolen from the safe implies that this was not a random attack, and is more likely to be someone close with Michael – possibly one of the two other people that had the combination to that safe. Could this have been his estranged wife and business partner, or his mistress that claims that the two had planned to get married?

Money seems to be the primary motive for the crime due to the missing wallet and money from the safe, as opposed to a crime of rage or passion Other than the financial difficulties that he and his estranged wife had however, it may be possible that he owed the wrong people money. Was Diane struggling so much with her bouncing cheques that she started fantasising about his life insurance money?

There is a possibility that the money and wallet were taken to make it look like a robbery to mislead the police, which implies that there could have been another motive. Had Michael’s affairs finally caught up with him, leading to fatal attack? And if so, had it been a jealous estranged wife, the woman he’d been conspiring to marry or one of the many rumoured others?

The murder weapon was never found, and no items were reported missing from the house, which implies that the murder was premeditated as a weapon must have been brought to the scene and then taken away afterwards.

The interaction that Michael had with his sister, only one month prior to his murder suggests that he may have known that he was going to die. Is it possible that Michael was involved in something a little more shady than his plastering business and he had gotten into some sort of trouble?


Photo: Sister Katrina Fitzpatrick still believes she knows who killed Michael.

The final, and most troubling point, is that his family still threw a New Year’s party despite Michael being reported missing. This was not a usual thing to occur with Michael, and the host being missing from a party seems to raise no suspicion to anyone, which appears odd. A friend that had been at the party had described it as being ‘100% relaxed’ with no suspicious whispering or conspiring. There was no odor present at that point and the family seemed happy and normal. Were there people at that party that knew about the body close by?

Current Investigation:


Photo: Michael’s coffin being carried at his funeral.

Thirteen years after the murder and no charges have ever been made, and no new leads have been investigated for years. It seems like the only way there will ever be answers is if someone speaks up about what happened. After all this time it must be a huge burden to carry, and it is hoped that the family are able to get closure soon.

Detective Sergeant Martin Robertson said there were several persons of interest and called for anybody with information to contact Crime Stoppers on 1800 333 000.


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