<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (May 2008) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (May 2008) (Learn how and when to remove this template message) </Td> </Tr> <Table> <Tr> <Th_colspan="2"> Ben Stone </Th> </Tr> <Tr> <Td_colspan="2"> Law & Order character </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> First appearance </Th> <Td> "Prescription for Death" </Td> </Tr> <Tr> <Th> Last appearance </Th> <Td> "Old Friends" </Td> </Tr> <Tr> <Th> Portrayed by </Th> <Td> Michael Moriarty </Td> </Tr> <Tr> <Th> Time on show </Th> <Td> 1990--1994 </Td> </Tr> <Tr> <Th> Seasons </Th> <Td> 1, 2, 3, 4 </Td> </Tr> <Tr> <Th> Credited appearances </Th> <Td> 88 episodes (total) </Td> </Tr> <Tr> <Th> Succeeded by </Th> <Td> Jack McCoy </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Ben Stone </Th> </Tr>

When did ben stone leave law and order