Australian schoolgirl Tiahleigh Palmer was 12 years old when she came home from dance class and was murdered by her foster father.
Hours earlier, Rick Thorburn had learned that that his teenage son, Trent, had sexually assaulted her. They feared she might be pregnant.
So the Queensland man killed Tiahleigh and dumped her near-naked body on a river bank.
On Friday, he was sentenced to life in prison. Justice David Boddice described the murder as "cold, calculating and callous".
Thorburn's wife and two sons have already been jailed for their roles in a case which has horrified Australia.
The killing also led to a review of Queensland's foster care system, and changed police alerts about vulnerable children.
Tiahleigh had been in care since she was seven. She had been living full time with the Thorburn family in Logan City, 45km (28 miles) south of Brisbane, since January 2015.
On 30 October that year, her foster family reported her missing.
Rick Thorburn told police he had last seen her when he dropped her off at school that morning.
After a police search - which Thorburn helped with - Tiahleigh's body was discovered a week later, on a river bank about 50km (31 miles) from the family home.
She was found in just her underwear, and her body was so decomposed that police could not determine at first whether it was a boy or girl.
About 600 people attended the funeral in November, where Thorburn, wearing a purple shirt emblazoned with Tiahleigh's name, helped carry the casket.
The police investigation into her death continued but with no substantive leads. A post-mortem revealed a bruise on Tiahleigh's head but no further clues as to how she died.
Police interviewed scores of school friends and offered a A$250,000 (€160,000: £140,000; $190,000) cash reward for information.
Tiahleigh's birth mother, Cindy Palmer - who had only recently given up her parental rights - made a public appeal.
Seven months after the killing, police received a phone tip-off. An anonymous caller told them Trent Thorburn - Rick Thorburn's son - may have had sex with Tiahleigh. Police were also informed of a family meeting that took place on the night she was murdered.
The Thorburns were hauled in for questioning and, it later became clear, lied to police.
Police then bugged the family home where they heard the parents coach the sons on their stories. They also found a Facebook messenger chat where Trent confided in his cousin that he may have got Tiahleigh pregnant.
In September 2016, police charged Rick Thorburn with the murder of Tiahleigh, interference with a corpse, perjury and attempts to pervert the course of justice.