Testimony in the murder trial of Kyle Deemer began Tuesday with an eyewitness account. Kevin Zimple was on his way to Marshalltown from Traer on Highway 14 when he noticed a car going into the ditch. He pulled off and saw a woman screaming into her cell phone. When he asked what was wrong she told him "my ex-husband just shot him." Then Zimple said he heard a male voice tell her, "And you're next." When Zimple saw the gunman, he said his reaction was to leave the scene to protect his kids. He pulled forward, heard a pop and then saw the woman motionless on the shoulder of the road. Later, witnesses testified Deemer had a hard time dealing with the end of his relationship with Jessica Deemer, his estranged wife. Deemer is accused of shooting her, and her friend Bryce Mercer, both 24, in northern Marshall County Oct. 17, 2008. Jessica Deemer and Mercer were traveling together at the time they were shot, according to the Marshall County Sheriff's Office.