A man who violently shook a five-week-old baby in a southeast Queensland caravan park has been sentenced to 13 years’ imprisonment over the child’s death.

Robert Alan Gee showed no emotion as Justice Martin Burns handed down the sentence in the Brisbane Supreme Court on Friday, dressed in a T-shirt and shorts as the long-running case over the 2021 death of baby Michael Willmot reached its conclusion.

The sentencing relates to the death of Michael, who was just 37 days old when he suffered catastrophic brain injuries after being shaken and thrown onto a couch at a Daisy Hill caravan park in Logan while in Gee’s care.

Robert Alan Gee and Kristie Lee Willmot have both been sentenced over the death her baby, Michael Willmot. Picture: Supplied
The court was told the incident occurred after Gee – who was not Michael’s biological father – became frustrated with the baby’s crying during a brief period he was left alone with him, during which he shook the baby before throwing him down onto a couch.

In the days that followed, Michael’s condition worsened significantly, but he was not taken for medical treatment.

Michael’s mother, Kristie Lee Willmot, had left her baby in Gee’s care for less than an hour on the day he was injured while she went out to obtain drugs.

She later became aware he was unwell but did not seek immediate medical assistance, fearing he would be taken away from her by Child Safety.

Michael died on June 14, 2021.

The pair were initially charged with murder.

Gee pleaded guilty to a charge of manslaughter at an earlier court appearance.

Willmot also pleaded guilty to Michael’s manslaughter and another count of cruelty to children.

In October 2025, she was sentenced to four years’ imprisonment, suspended after time already served, and walked free from court.

Baby Michael Willmot was just 37 days old when he died in June 2021. Picture: Supplied
Outside court, Michael’s godmother and family spokesperson, Malliree Reilly, said the family welcomed the outcome.

“We are happy with the sentencing that got passed down today. We’re happy that this person is off the streets, he can no longer hurt any other woman or children,” Ms Reilly said.

She said it had been “confronting” to hear details of Gee’s history during the proceedings, and expressed concern that someone with a serious criminal background had still been in a position to have access to children.

Baby Michael pictured with godmother Malliree Reily. Picture: Supplied
While acknowledging nothing could undo what happened, she said the family wanted greater awareness about how people with violent histories were able to remain in the community.

Ms Reilly said the family had lived with the “horrific” circumstances of Michael’s suffering every day since 2021, explaining there was nothing that could ease the pain of knowing how he died and the injuries he endured.

She also said the family had previously raised concerns about Michael being placed in his mother’s care, and believed warnings were not acted on at the time.

Malliree Reilly outside of the Brisbane Supreme Court following the sentencing. Picture: NewsWire / John Gass
Despite the tragedy, she said the family would continue to remember Michael as a “very sweet, beautiful baby boy” who was loved, and said they would continue speaking his name and honouring his memory.

She added the family hoped their experience would encourage others to speak up when they saw warning signs and to check backgrounds where possible when children were involved.

Gee will be required to serve at least 80 per cent of the sentence, including time already served, before being eligible for parole.