The high school tennis coach and Cub Scout leader from Dubuque, who is accused of killing his two children and attempting to kill his estranged wife, made an initial court appearance yesterday. 38-year-old Michael Walker appeared in Dubuque County District Court on two charges of first-degree murder and one count of attempted murder. Police say Walker indicated he intentionally suffocated his two children and then went to his estranged wife Karen’s apartment and attempted to stab her to death. Karen Walker was in critical but stable condition yesterday at Mercy Medical Center in Dubuque. Her family has requested that her condition not be released. Michael Walker’s being held on a one-point-five million dollar bond. A preliminary hearing on the case is set for February 27th.