The former teacher was sentenced to a maximum of 24 years for the crime.
The NSW Court of Appeal rejected his challenge to his murder conviction in June 2024, finding that there was no miscarriage of justice despite errors in Justice Harrison’s decision.
Dawson then took the matter to the High Court where a panel of six judges shot down his final bid today.
“There is no reason to doubt the correctness of the decision of the Court of Criminal Appeal including its dismissal of the appeal,” the judges wrote.
“Accordingly, it would be futile to grant an extension of time (to appeal).”
That case upheld findings by the state’s District Court that the ex-teacher had engaged in unlawful sexual activity with the student who eventually moved into his home before she turned 17.
The carnal knowledge sentence added one year to his non-parole period which expires in 2040.
