They told me that they only keep the records of Lancaster Quarter Sessions, and that records of more serious offences tried by the Assizes were held by the British National Archives.
But they did have some information about Moorbee after all:
However a search of our electronic catalogue found the following entry from QJC/1, a calendar of prisoners:Prisoner forename: Joseph
Prisoner surname: Moorbee
Offence: Burglariously broken and entered dwelling house to steal a gold watch and other
articles; also again to steal a small purse, 2s., 3 silk handkerchiefs & other
Hundred: West Derby & Leyland
Place: Atherton/Tyldsley w' *
Date of offence (if given): 19 May 1821
Verdict if given (based on annotations on the printed calendar): Guilty
Sentence if given (based on annotations on the printed calendar): Death, reprieved
Thank you, ACS Record Office, Lancashire, England.