Iraqi Kurdish, Sunni and Shi'ite negotiators are trying to reach agreement on a draft constitution ahead of Monday night's deadline. The officials are trying to overcome differences on political autonomy, women's rights, revenue distribution, and the role of Islamic law in the new charter. An Iraqi spokesman (Laith Kubba) says lawmakers may have to vote to extend negotiations for a second time, if an agreement is not reached by the deadline. Meanwhile, the U.S. military opened a criminal probe into the death of a relative of Iraq's ambassador to the United Nations. The son of Ambassador Samir Sumaidaie's cousin was killed in June as U.S. Marines searched his home in western Iraq. In other developments, an Iraqi family of five was found shot dead in Samarra, and a U.S. soldier was killed by a roadside bomb near Tikrit Sunday. And two American soldiers were killed when their vehicle rolled over during a patrol near Tall Afar.