Terence Darrell Kelly attempted to appeal against his 13-and-a-half years' jail term for snatching the girl at the Blowholes campsite, about 70km north of Carnarvon in the early hours of October 16, 2021, as her parents slept.
Cleo was missing for 18 days before finally being found by police alone in a room at a property in Carnarvon on November 3.
Cleo Smith's kidnapping sparked one of the biggest police searches in WA history. (Richard Wainwright/AAP PHOTOS)
Her kidnapping by the 37-year-old sparked one of the biggest police searches in WA history and made headlines worldwide.
Sentencing Kelly in the District Court in April 2023, Chief Judge Julie Wager described the fear, distress and trauma caused to Cleo and her parents as "immeasurable".
"Eighteen days without contact or explanation, and with hours totally on her own and no access to the outside world, would have been very traumatic," the judge said.
Under his sentence Kelly, who pleaded guilty to taking Cleo, will be eligible for parole after serving 11 years and six months.
In February, his lawyers argued four grounds for appeal in the WA Court of Appeal.
Ground one alleged that the Chief Judge Wager erred in law and fact in finding that the appellant's use of methylamphetamine had a significant role in the offending.Â
Cleo was found after 18 days in a room at a Carnavon property. (Richard Wainwright/AAP PHOTOS)
The second and third grounds for appeal alleged that Chief Judge Wager erred in law in applying two principles of law, including by failing to sufficiently acknowledge his deprived, traumatic childhood and mental impairment when assessing his moral culpability.
The three appeal court judges dismissed grounds one, two and three in a Perth court on Monday.
"Her Honour did not misapply any legal test applicable to the determination of whether the appellant's use of methylamphetamine had a significant and causal role in the offending," Justice Michael Buss said in the decision.
The three judges disagreed on the fourth ground of appeal that alleged the sentence was manifestly excessive, with Justice Buss finding it had been made out and that he would have reduced Kelly's sentence to 12 years due to the mitigating factors.
Justices Robert Mazza and Stephen Hall came to a different conclusion, dismissing ground four.
"The sentence that was imposed upon the appellant was severe, but it was an appropriate reflection of the extraordinarily serious nature of the offence the appellant committed," they said.
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