DERRY — A leading former member of Northern Ireland’s largest unionist-loyalist paramilitary group was assassinated at his home in Belfast. Jim Gray, a former commander in the Ulster Defense Association (UDA), was shot late Tuesday several times at close range in his doorway by two gunmen. His killing came six months after his ouster from the UDA, of which he was a commander, following a dispute with his former colleagues. The 43-year-old ex-militant was out on bail and awaiting trial on money laundering and stolen property charges. Gray was arrested near the border of the Irish Republic in April, and was thought to be trying to leave Northern Ireland.