Prosecutors have released new evidence in a Cedar Rapids murder case. The Linn County Attorney filed first-degree murder charges yesterday against 29-year-old Carloss Robinson in the Monday stabbing death of 20-year-old Christina Sanoubane. Robinson’s father, Tim, says his son didn’t commit the crime.Tim Robinson says his son has been in little trouble in the past, but nothing like this.Investigators say they identified Robinson’s footprints in the victim’s blood. At first, Robinson denied being in Sanoubane’s apartment but latertold police he was there, but didn’t harm the victim. Robinson’s fiancée, Tameca Sanders, says police should not have that statement from Robinson as they denied him an attorney.Police say Robinson waived his right to an attorney in writing. His lawyer says Robinson was not aware his family had hired an attorney and told police he didn’t have one. A judge has ordered the public defender to take the case for now.