An Iranian judge who sentenced several reformist dissidents to jail, including hunger-striking reporter Akbar Ganji, was shot dead in his car by a lone gunman riding a motorcycle.
Witnesses saw the passenger seat of the saloon car drenched in blood and the driver's window shattered by gunfire.
"Hassan Moghaddas was shot and martyred after leaving the court building," judiciary spokesman Jamal Karimirad told Reuters, after initially identifying the dead man as Massoud Moghaddas.
"We do not know anything about the identity of the assassin," he added.
Tehran Chief of Police Morteza Talaie said the judge had been killed by a lone assassin armed with a pistol.
State television reported he was deputy prosecutor for Tehran and had been shot twice.
He had been presiding over the case of Akbar Ganji, a journalist who was imprisoned in 2001 following a string of stories he wrote linking officials to the murder of dissident intellectuals.
Ganji's wife says her husband is in very poor health because of a hunger strike.
Karimirad said Moghaddas had presided over sentencing seven dissidents in 2000 who had attended a Berlin conference on reform in the Islamic Republic.