Thorburn entered the court just after 10.30am wearing long dark pants and a light blue button-up shirt and wiped his eyes while pleading guilty to the charges. In a letter submitted to the court written by Thorburn, he said not a day went by when he wasn’t haunted by what he had done. The courtroom was full, and several Tiahleigh supporters were present, including her mother Cindy Palmer. Tiahleigh Palmer. Credit:Queensland Police Service Thorburn’s wife and two sons have also been jailed.

Trent Thorburn, who admitted to sexually abusing Tiahleigh, his foster sister, was jailed for a maximum of four years in September 2017 after pleading guilty to four charges, including incest. His older brother Joshua Thorburn was sentenced to three months in July 2017 after pleading guilty to perjury and attempting to pervert the course of justice. Rick's wife Julene Thorburn served six months in jail after pleading guilty on November 2017 to perjury and attempting to pervert the course of justice. Prosecutor Carl Heaton QC told the court a phone call to Crime Stoppers as well as police-installed covert listening devices led to the arrest of Rick Thorburn. Cindy Palmer (left), the mother of murdered schoolgirl Tiahleigh Palmer, is seen arriving at the Supreme Court in Brisbane on Friday. Credit:AAP/Dan Peled

A call to Crime Stoppers about seven months after Tiahleigh’s disappearance tipped off investigators it was believed Trent Thorburn had sex with her. Listening devices were then installed at the family’s home, which captured conversations between the family members, including Thorburn telling his wife and sons to “stick to the story” about him dropping Tiahleigh at school and to keep Trent’s relationship with Tiahleigh “quiet”. Trent Thorburn was jailed after he pleaded guilty to sexually abusing his underage foster sister. Credit:Instagram Mr Heaton said it had been determined the 12-year-old was killed between 8pm and 11pm on October 29, but the body was too decomposed to determine a cause of death. The only injury noted was a bruise on her scalp.

Mr Heaton recommended a non-parole period of 20 years for the charge of murder and no allowance for a sentencing discount because of Thorburn's guilty plea. He added the sentences for the other four charges should run concurrently. Defence barrister Greg McGuire revealed Thorburn had spent time in care after the death of his mother when he was nine years old. He added Thorburn had attempted suicide shortly after his arrest and had also lost a considerable amount of weight. Loading Replay Replay video Play video Play video

In sentencing, judge David Boddice described Thorburn’s act of murder as cold, calculating and callous. “You murdered a 12-year-old child who was in your care because her own mother was unable to properly care for her,” he said. “The reasons for that murder and your conduct can only be described as cold, calculating and callous.” Thorburn, who pleaded guilty to the murder of his foster daughter, carried her coffin at the funeral. Credit:AAP/Dan Peled Judge Boddice said Thorburn showed no respect for Tiahleigh, even in her death.

He said he gave regard to Thorburn’s plea of guilty and personal circumstances, including his criminal history, but said none of the circumstances explained his horrendous actions. Thorburn will be eligible for parole on September 12, 2036. Tiahleigh's mother Cindy Palmer made a brief statement outside the court shortly after Thorburn’s sentencing. “Today marks the end of a long and painful fight for justice for Tiahleigh,” she said. “As her mother, no sentence will ever be enough.

“Tiahleigh was a beautiful young girl who had her entire life to look forward to. “Rick Thorburn took that away from me, from our family and most importantly Tiahleigh. “I need time to process today’s sentencing and to grieve with my family in private. “I would like to thank the community and the police for all their help and support throughout this tragic ordeal.” Regional crime coordinator for south-east region Detective Superintendent Kerry Johnson said he hoped Thorburn thought about the life he had cut short every day.

“What I’d like to talk about is first and foremost is Tiahleigh herself, a 12-year-old girl and as we know had her whole future ahead of her, which was cut short by this person,” he said. “It is the ultimate act of betrayal, she was put in a foster care situation where people were supposed to look after her and care for her and its the very same people who allowed this to happen. "It’s an absolute tragedy and inexcusable." Superintendent Johnson thanked the public and the media for their help during both Tiahleigh’s missing person case and the investigation after she was found deceased. “Without the public and media help in that it would have been an impossible task,” he said.

Child Safety Minister Di Farmer said Queensland had strong and robust system for the approval of foster carers. "Tiahleigh Palmer was the victim of an evil crime committed by Rick Thorburn," she said. Ms Farmer said in the wake of Tiahleigh's death, urgent reviews made more than 100 recommendations to improve child safety in Queensland. "Implementation began before the reviews were completed and is continuing," she said. "None of them are any consolation for Tiahleigh's murder.