There is an entry for a Thomas Richards, 25, in the Denbighshire Criminal Records, Quarter Sessions held on 4 August 1840. Crime was Larceny and was sentenced to transportation, 7 years.
He seems to have been recorded for similar crimes earlier as there is a similar entry in June that year when he was sentenced to imprisonment.
Add - two earlier entries (1824 and 1838) for Larceny but not sure if this was the same person. The 1838 one was of a similar age.
Gadget