Jake Barrett in the ITV police series The Gentle Touch (1980–1984) and George Palmer in the BBC soap opera EastEnders (1996–1998).
He also made guest appearances in several popular television shows including Coronation Street, Z Cars and The Sweeney.
After this he continued to play guest roles on established British television series such as Casualty, The Bill, Maigret and Wycliffe.
In 1995, he played Col. Forster in the BBC's acclaimed adaptation of Jane Austen's Pride and Prejudice.
Moriarty has often been cast in police or criminal roles, and has played a police officer in at least ten different British television series; Z Cars, The Gentle Touch, Between the Lines, A Touch of Frost, Maigret, Peak Practice, Expert Witness, Murder Most Horrid, Doctors and Ashes to Ashes.