BAGHDAD, Iraq - U.S. troops captured a key lieutenant of radical Shiite leader Muqtada al-Sadr during overnight clashes in Najaf that killed 24 people and wounded nearly 50, hospital and militia officials said. Riyadh al-Nouri, al-Sadr's brother-in-law, offered no resistance when American troops raided his home during a series of clashes in this Shiite holy city, according to Azhar al-Kinani, a staffer in al-Sadr's office in Najaf. The capture of al-Nouri would be a major blow to al-Sadr's al-Mahdi Army, which has been battling coalition forces since early April. Al-Sadr launched his uprising in response to a crackdown by coalition...