What happened to Donal O'Sullivan? Details explored ahead of Buried in the Backyard on Oxygen

Oxygen's Buried in the Backyard is all set to revisit the disappearance and murder of Florida-based entrepreneur Donal O'Sullivan. The entrepreneur was brutally murdered and buried in a freezer bought with his money on his own property. The case of the man trying to help and aid his younger friends sent a shockwave across the low-key town of Melbourne, Florida.

The episode, titled Deep Freeze, originally premiered on Oxygen in December 2021 but has remained an enduring case. The synopsis of the episode reads:

"An entrepreneur forges an unlikely friendship with a ragtag group of skateboarders, but when he vanishes and signs point to foul play, police wonder whether he was really a friend or a target."

The episode will re-air on April 19, 2024, at 8 pm ET on Oxygen. Ahead of the episode, this article will break down what happened to the victim.

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Who was Donal O'Sullivan and what happened to him?

O'Sullivan's unlikely friendship with the skaters led to his untimely death (Image via Pexels)

Donal O'Sullivan was a very likable and successful businessman from Florida, often described as a very kind soul. He was a successful tech entrepreneur who retired early. Donal started his business with his brother Dennis, which was pretty successful. However, Donal often suffered from pangs of depression.

He lived in Georgia before he moved to Florida, where he encountered and made friends with a group of skaters. He was 42 at the time, making him much older than the ragtag group he was friends with and they often hung out in skate parks near a bridge. Donal was trusting and soon became good friends with many of the younger boys there. However, not all of his younger friends seemed to have the good intentions he did.

In September 1998, some of Donal's older friends noticed that they hadn't seen him for a while. They got Dennis involved and informed the police, who found out that there had been large sums of money withdrawn from Donal's bank account. They also noted the involvement of a particular young man who claimed to be Donal O'Sullivan's son.

However, the family confirmed that Donal had no son, which sped the investigation up. After the police talked to his skater friends, they went to search Donal's house, which led to a shocking discovery.

The authorities found a mattress covering a carpet that was drenched in large amounts of blood. Police also found bins in the house that seemed to be a part of a deep freezer, but found no such freezer in the house.

This became an important clue that ultimately led the authorities to 26-year-old Daniel Tennity, one of Donal's skater friends, whom the victim helped out a lot. Donal O'Sullivan paid the rent for the house where Tennity and another friend lived. After visiting the house and finding out that Tennity was violating his parole, the authorities apprehended him.

Though Tennity tried to misguide the police, they found a freezer receipt that led them to a remote plot in Canaveral Groves. The police dug out a deep freezer, that had the victim's body, buried in the plot, which was also purchased with Donal O'Sullivan's money by Tennity.

The prosecution alleged that Tennity murdered O'Sullivan when the latter found out that the young man was stealing checks from him. Tennity admitted to strangling Donal O'Sullivan to death and he was sentenced to 40 years in prison for the murder.

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The re-airing of the episode of Buried in the Backyard will cover this case in more detail. Stay tuned for updates.