Committal hearing listed for murder accused Tara Maree Richardson over death of Tarrin-Macen Kenneth O’Sullivan

New details about the injuries allegedly suffered by a four-year-old Qld boy, whose mother claimed he had drowned in their backyard pool but is charged with his murder, can be revealed.

Tarrin-Macen Kenneth O'Sullivan with his parents Andrew O’Sullivan and Tara Richardson. Tarrin-Macen died on Sunday, August 29, 2021. His mother Tara Richardson (right) is charged with her murder and misconduct with a corpse. Picture: Contributed

Lawyers for a woman accused of murdering her four-year-old son have pushed to question her partner in an upcoming committal hearing, labelling him a “crucial” witness because he found and pulled the little boy from the pool.

This comes as new details about the case can be revealed for the first time including that the child had injuries to his face and body and something in his mouth when he was found dead, there was a suggestion of “dry drowning” and multiple expert witnesses were involved in the police case.

Tarrin-Macen Kenneth O’Sullivan’s naked body was found in a pool at a Munbura home in the Mackay region on August 29, 2021 and police allege his mother was the only person home at the time of his death.

She is charged with murder and interfering with a corpse.

No pleas have been entered.

Tara Richardson, 46, has been charged with the murder of her four-year-old son Tarrin-Macen Kenneth O'Sullivan after he was found face down in a poll near Sarina in August 2021.

Police allege the little boy was dead before he entered the water, and Ms Richardson phoned triple-0 claiming her son had drowned.

Ms Richardson has remained in custody on remand since her arrest on December 8, 2023 with the case listed for a directions hearing on Wednesday, April 30, 2025 when Magistrate Damien Dwyer determined which witnesses her lawyers could question at a committal.

Legal Aid Queensland solicitor Molly Mahlouzarides argued Jason Richardson had “crucial observations” because he had been the one to find Tarrin-Masen in the pool.

“He’s a significant witness because of … the timing of when he last sees the child alive, he assists in the search, he discovers the child in the pool,” Ms Mahlouzarides said.

She said Mr Richardson could also give observations “about the scene such as the pool fence being difficult to access, an object that he found in the child’s mouth that’s unidentified”.

In her application Ms Mahlouzarides was pushing for further clarification and “more recollections … particularly where they underpin the various expert opinions given”.

Tarrin-Macen Kenneth O'Sullivan is remembered as a technology-mad youngster after he tragically died in hospital after being pulled from a pool at Munbura southwest of Mackay on Sunday, August 29, 2021. Picture: Contributed

However, Magistrate Damien Dwyer rejected calling Mr Richardson as a witness, agreeing with prosecution that he had already provided sufficient evidence.

Mr Dwyer has allowed five expert witnesses including the doctor who performed the autopsy, a dentist and a biomechanical engineer to be questioned on some points during the committal but had rejected their cross examination on others.

The rejected scope included cross examining an expert witness about literature relating to “dry drowning”.

Ms Mahlouzarides also submitted to cross examine an expert witness on supporting or excluding Tarrin-Macen’s cause of death.

Prosecutor Kat Pollard said this witness had already outlined in her statement “that the cause of death in her view through an objective sense is the uncertainty”.

Mr Dwyer asked where this witness had excluded various causes of death.

The court heard in her statement she mentioned “the possibility of a choking collapse into the pool” and “the possibility of the victim being smothered prior to entering the pool”.

Mr Dwyer said other possible causes including strangulation and head injury were not addressed.

Mackay police have declared a crime scene at a Munbura home after declaring a homicide investigation into four-year-old Tarrin-Macen O'Sullivan.

“And isn’t that very important, that they be excluded,” Mr Dwyer said.

One expert witness, a dentist, has given evidence regarding injuries to Tarrin-Macen’s mouth and how they might have been sustained.

“He refers to either a blow or significant pressure pushing the lip against the teeth,” Ms Mahlouzarides said, adding she wanted to question him further for more detail on the mechanism

“I won’t allow that,” Mr Dwyer said.

He did allow Ms Richardson’s lawyers to question the doctor who performed the autopsy about regarding injury time frames.

Ms Mahlouzarides had also wanted to question experts “who purport to exclude the drowning on the basis that the child does not have diatoms within the body” but Mr Dwyer said he was not going to allow that.

The court heard the prosecution had rejected all aspects of the application to cross examine witnesses in a 115 page refusal, with Ms Pollard calling it a “fishing expedition”.

Ms Mahlouzarides said that suggested there was no aim or basis to the application, and argued it was brought to better understand and explore the basis of the expert opinions.

The matter was listed for a one-day committal hearing in early September.

Originally published as Committal hearing listed for murder accused Tara Maree Richardson over death of Tarrin-Macen Kenneth O’Sullivan