John Ahern was found guilty of the crime of burglary at his trial in Cork on 25 September 1850 and sentenced to seven years transportation.
The Irish Transportation Database states that John Ahern was imprisoned in Cork prior to his transportation. It is possible that this is his prison record which would give an approximate birth year of 1833. The crime given here was "Stealing Money (Burglary)".
John Ahern's convict records in Australia have not yet been located.