It's what some investigators call the most bizarre case they've ever seen.
What happens when you have all the evidence needed to solve a murder, but there are no answers to be found?
The decades-old homicide case of Marvin the Mummy presented that challenge - and it all started in Adams County.
The investigators who were on the scene nearly 30 years ago recall every detail of that day.
Mike Ernst is a former Illinois State Police detective, with 44 years of law enforcement experience.
His former colleague was Larry Hood, former crime scene analyst with the Illinois State Police.
If you ask them about Marvin the Mummy, the details begin to flow.
"I was in the office, and we got a call from the Sheriff's Office," Ernst said.
"(They were) requesting assistance with a potential body that had been found in an abandoned rock quarry," Hood recalled.
Just a few miles southwest of Lima, the body of a white male in his 20s had gone undiscovered for months. That is, until the day a group of mushroom hunters found the body next to a lake in an abandoned rock quarry.
When investigators arrived on the scene, they found that the man's body had literally been mummified: preserved by the winter's cold, then withered by the spring sun.
There were several pieces of evidence found at the scene, but not a single piece hinted at the man's identity.
As a result, Larry Hood christened the subject Marvin the Mummy, and it was clear from the beginning - Marvin was murdered.
"The decedent had undergone a massive amount of trauma to certain areas all over his body," Hood said.
Trauma that included severe fracturing of the skull, a severed aorta, and numerous other gaping wounds, both in the man's torso and legs.
But officials had plenty of leads to start on thanks to the evidence found in the quarry.
There was a t-shirt found on the body from Captain Anderson's Restaurant in Panama City Beach, Florida.
The man's hands were preserved well enough to allow investigators to pull fingerprints from all 10 fingers.
And there was one other signature clue.
"It was also of particular interest that we were able to discover a tattoo on his right forearm," Hood said.
During the autopsy in Springfield, officials were able to uncover a large tattoo beneath months of skin decay.
It depicted a Grim Reaper-style skeleton holding a shotgun that was being fired.
But something about the tattoo immediately stood out to Hood.
He said there was nothing professional about it, and that it was most likely inked in a prison. It's the kind of tattoo don't forget once you see it.
Investigators felt confident that, if nothing else, the tattoo would help lead them to a suspect. Somebody out there, maybe an inmate, would have to remember seeing that tattoo before.
"I felt good about the case as far as identification, I thought this guy was going to be identified really soon," Hood recalled.
His tone quickly changed. "Well, as it turned out, that wasn't the case."
Things just weren't adding up - investigators came up empty time and again.
Hood and his colleagues searched thousands of fingerprint records to no avail.
"The criminal, the military and the civilian files were all searched at the FBI with negative results," he said.
Days of investigation turned into weeks.
The t-shirt found at the scene was no help.
The same went for the dental records obtained from the corpse.
Weeks turned into months.
Investigators sent out a sketch of the tattoo to law enforcement agencies all around the country, again, with no results.
Months turned into years, and investigators still were no closer to identifying the body or a suspect than they were on day one.
"It was the only case I'd ever seen where we could not identify the body," Ernst said.
KHQA spoke with Adams County State's Attorney Jon Barnard, who was in private practice in the area in 1985.
He also remembered the case well.
When asked just how absurd it was to have all of the evidence needed to track down an identity, but still come up with nothing, he summed it up well.
"Well ... let's just put it this way; there has been one case like that ... it's this one," Barnard said.
Even today, almost 30 years later, you can sense the frustration from those who were there.
"I worked on it for five years before I retired ... we put in a lot, a lot of hours," Ernst said, shaking his head.
But one thing you'll learn from criminal investigators?
Until it's solved, a case is never closed.
"I just kept saying in the back of my mind that someone is going to run into someone, somewhere that knows something about this case," Hood said.
As it turns out, Larry Hood was right.
There was somebody, somewhere who had the answers.
View the conclusion to this story, Marvin the Mummy: Revisited, Part 2, here.