A Knox County Grand Jury has indicted a Mount Vernon man who's son shot and killed himself with an unsecured .45 caliber handgun.25-year-old Joshua Heagren faces charges of child endangering and negligent homicide in the May death of his 3-year-old son Lucas. Prosecutors say the boy found his dad's loaded gun laying on top of a television. Heagren is due to appear in court next week.