An incomplete list of Police Magistrates, Assistant Police Magistrates, Visiting Magistrates, Magistrates and Justices of the Peace operating in Van Diemen's Land during the convict period up to 1849. This list may assist in deciphering the name of the magistrate whose initials appear after a charge on conduct records.
The Guide to Tasmania, by Hugh M. Hull: List of Magistrates in Van Diemen's Land/Tasmania up until 1858
http://classic.austlii.edu.au/au/journals/AUColLawMon/1858/1.pdf (document pages 16 - 21)
The Magistrates' Manual for the Colony of Victoria, printed 1852