They say he has not been involved in revenge attacks against minority Sunnis, which are often attributed to the Mahdi Army and other armed Shiite groups. Before Hussein's fall, Mohamed did a stint in Abu Ghraib prison for car theft; he also had misfortune late last year when the taxi he was leasing was incinerated after a nearby horsecar full of gasoline cans collided with a minibus. Now he plans to join the Iraqi army and will maintain ties to Mr. Sadr's militia.
The bearded young man says he began to follow Mr. Sadr during the anti-US uprising in Najaf in August 2004, but didn't begin volunteering until last February, when the important Shiite shrine in Samarra was destroyed, setting off sectarian killings that have left thousands dead.
Mrs. Methboub, the family matriarch, speaks highly of Mohamed's decision and describes how his unit stopped a kidnapping of a boy by gunmen in three BMW cars near the national theater. "They handed the boy back to his father," she says. The kidnappers were taken to a Sadr office, where Mahdi Army officials "beat them very hard" and found they were policemen who had been planning the kidnap for seven months, for ransom.
"I blame the police," says Methboub, disgusted. "Instead of protecting people, they are trying to kidnap and kill people."
Mohamed's unit has made arrests at gambling dens, and sealed off shops that sell alcohol before opening time, lobbing percussion grenades at them to break windows and send a message to stop.
Sadr's people also control the price of rent for the poor and try to limit the cost of a bottle of propane gas to 1,500 Iraqi dinars – about $1. In the Methboub neighborhood, each bottle sells for 10,000 dinars.
"Every good Muslim should join the Imam Mahdi Army," says Mohamed. He accuses the rival Badr Brigade, a Shiite militia created in exile in Iran more than 20 years ago, of running kidnap gangs for ransom. Shiite gunmen have also been accused of mounting "death squads" that target Sunnis, out of the Ministry of Interior.