Lawyers for the American Civil Liberties Union of Colorado filed suit Tuesday against three Colorado State Patrol officers and two training supervisors in the shooting death of an unarmed Grand Junction man.Jason Alan Kemp, 31, was shot at point-blank range and killed last summer when he refused to allow officers to enter his home without a search warrant, according to the ACLU.Kemp was suspected of having crashed his pickup around the corner from his home, according to the state patrol. He apparently walked home and was there when troopers arrived a short time after the crash.Witnesses said that troopers pounded and kicked on Kemp's front door at 103 Glade Park Road, Unit B, in the Redlands area. He refused to open it, telling troopers to get a search warrant. One witness said Kemp was shot after troopers fired pepper spray through a small opening in the door.Trooper Ivan Lawyer told the grand jury he saw a flash and thought he had been shot, so he fired at Kemp.The ACLU lawsuit was filed on behalf of Connie and Keith Kemp, the parents of Jason Kemp. It alleges that Lawyer shot Kemp in the chest and asserts that two additional troopers at the scene contributed to his wrongful death as they attempted to break down Kemp's door after he told them they needed to get a warrant."The state troopers were investigating a minor accident that resulted, at most, in minimal damage to a neighbor's lawn," said Mark Silverstein, ACLU legal director. "They suspected Jason was responsible for this minor accident and may have been driving under the influence of alcohol. However, that provided no legal justification for proceeding without a warrant, drawing their guns, and attempting to kick down Jason's front door. It certainly provided no justification for shooting him dead."Silverstein said the case is a Fourth Amendment issue."Jason was killed because he did what every American has the right to do. He insisted that police comply with the Fourth Amendment and obtain a warrant before entering a person's home," Silverstein said.A Mesa County grand jury indicted Lawyer and Corporal Kirk Firko in connection with the incident last fall. While declining to charge Lawyer with second-degree murder or manslaughter, the grand jury did return indictments for criminally negligent homicide, second-degree assault, criminal trespass and other charges. Firko faces charges of criminal trespass and criminal mischief. Sergeant Chad Dunlap was not charged with any crime."Two supervisory officers -- a corporal and a sergeant -- were present at the scene and supported or participated in this lawless action of forcefully breaking into a home without a warrant to investigate a minor DUI," Silverstein said. "Only recklessly deficient training could account for supervisors' failure to stop the illegal warrantless entry before it resulted in the tragic escalation that unjustifiably took Jason's life."The suit was filed in federal District Court.