Carnahan was always the chief suspect in the June 17, 1985 disappearance and murder of the former beauty queen from Nixa, but he wasn't officially charged with her murder until August of 2007 when new DNA evidence was submitted to the state crime lab in Jefferson City.
Johns, who was last seen at a convenience store in Nixa, was reported missing after her sports car was found abandoned with the drivers side door ajar on the side of U.S. 160 in Nixa. Her body was floating in Lake Springfield by fisherman four days later.
Carnahan was questioned early in the investigation after it was reported that his distinctive truck was seen parked behind the 7-Eleven where Johns was last seen and, near Johns' vehicle on U.s 160 the night she went missing. However, no charges were filed against him after he was indicted by a grand jury for perjury in the case.
It wasn't until 2007 when a detective with the Highway Patrol had time on his hands to investigate cold cases that Carnahan was charged. Sgt. Dan Nash obtained a warrant to obtain DNA from Carnahan in August of that year. Two days after that warrant was served, Carnahan was arrested after his DNA matched semen found in Johns' body at autopsy.
Investigators had attempted to close the case in the late '90's and again in early 2003 using DNA, however, it wasn't until advances in the science in 2007 that they were able to obtain the match.
Carnahan is scheduled to be sentenced October 25th in St. Louis County where the case was moved on a change of venue.
Defense attorney Dee Wampler says he plans to file a motion for a new trial or an appeal.