Lawless was found dead in her car Nov. 8, 1992, at the northbound Highway 77 exit ramp off Interstate 55 in Benton, Mo.
She had been shot three times and struck in the head with a heavy object.
Josh Kezer, a teenager from Kankakee, Ill., spent 16 years in prison after jailhouse informants claimed he had killed the 19-year-old nursing student.
No physical evidence connected him to the case, and he was exonerated in 2009, three years after Scott County Sheriff Rick Walter reopened the case, believing the wrong person had been convicted.
Walter said when he reopened the case, he noticed the autopsy report mentioned some wounds, but no evidence to go with them.
"There was technology to do all this back then, but for some reason, it wasn't done," he said Wednesday night.
Walter said he knew investigators needed to exhume the body and swab the wounds, some of which appeared to have been scratches caused by fingernails.
Walter went to Lawless' family to get their blessing before pursuing a court order to exhume the body -- a process that took several months.
The sheriff said he wasn't sure the DNA would be intact after more than two decades, but he decided to try.
"The chances after 20 years of DNA even being gathered from the body all depends on how a body was prepared for burial," he said.
Washing the body with soap would have caused the DNA to deteriorate, but rinsing would leave it intact, Walter said.
"That's a variable that can affect whether DNA can be extracted," he said.
Walter said the body was in good condition.
"Forty-five samples were taken from various parts of her body," Walter said.
Investigators hope some of those samples contain skin cells belonging to the killer, but they likely will not know the result of their efforts for several months, he said.
"My hope and goal is to get DNA evidence to lead us to a suspect," Walter said.
Authorities began digging at 7:30 a.m. Tuesday, Walter said. By 5 p.m., the investigation was complete, and Lawless' body was reburied.
Walter said he, Scott County coroner Scott Amick and a scientist from Independent Forensic Services, based in the Netherlands, were present during the process.
On Wednesday night, Kezer said he was shocked when someone called him earlier in the day to tell him Lawless' body had been exhumed.
"You have to understand: This is an extremely old wound for the family and for me," he said. "When this happened to her, you know, it created a wound in a lot of people, and every time something like this comes up and then nothing happens as a result, it's like sticking a hot iron poker into the wound."
Kezer said exhuming the body could create false hope for the Lawless family if it doesn't lead to charges.
"If this is creating this kind of emotion in me, imagine what it's creating in her family," he said. "Naturally, it's opened a door of hope in her family, because they're thinking, 'The sheriff's not going to do this, and the scientists are not going to do this unless they're sure they've got something.' ... They need to honor that hope."
Kezer said he believes enough evidence exists to identify the killer, but no one has been charged.
"What I want to see come out of it is somebody getting the guts and the courage to charge the people who killed her," he said. "There is enough evidence ... in my belief to charge a couple of suspects. If they need more evidence in order to do that, to fill the need, do that."
Kezer was arrested after several jailhouse informants offered statements against him in exchange for leniency.
In overturning Kezer's conviction, Cole County Circuit Judge Richard Callahan had sharp words for the prosecutors and others involved in the case.
"There is little about this case which recommends our criminal justice system," Callahan wrote in 2009. "The system failed in the investigative and charging stage, it failed at trial, it failed at the post trial review, and it failed during the appellate process."
Three of the four informants who testified in the case changed their stories, and Callahan said then-Scott County prosecuting attorney Kenny Hulshof failed to turn over several key pieces of evidence to Kezer's lawyers.
Among that evidence was an interview with Scott City police in which Mark Abbott -- the only witness who could place Kezer in Missouri on the night of the killing -- named the person he claimed to have seen near the crime scene as someone other than Kezer.
In a letter to Callahan in May 2008, Abbott said he believed he was mistaken when he identified Kezer from a lineup as the man he saw.
Kezer said it is long past time to close the case.
"I feel like this has gone on long enough. The Lawless family, my family, we deserve some closure on this," he said. "This needs to be over, and quite frankly, her family and I deserve that. She deserves that. She's at peace right now, I believe, in heaven, but still ... she deserves that. I didn't even know the girl, and I understand that."
Highway 77 and I-55, Benton, Mo.