Burlington, NC -- The Alamance County Sheriff's Office is trying to piece together a crime with very little information.
On March 29, a body was found on Louis Graham Road in Burlington.
Investigators said the body had significant trauma and didn't have any identification.
The sheriff's office has followed up on several potential matches, but they eliminated all of them.
On Tuesday, they released a sketch of the unidentified man.
Authorities said he is a black man in his 20's, who was wearing a red shirt, jeans, and Air Force Ones.
Legally, there are four ways investigators can positively identify a body.
They could have to have a visual identification from the family.
But if they don't have that, it's tough to get number two, which is dental records.
The third way to positively identify a dead body is with fingerprints, but only about 25 percent of Americans have fingerprints on record.
Investigators could also identify a body with DNA, but normally, DNA is only on record for some criminals and military personnel.
"If he's never had a DNA swab taken and had that as part of a database anywhere, it makes all of those essentially, dead ends," said Dr. Bryan Brendley, associate professor of Biology at Guilford College.
Brendley, who has done extensive research on cold cases, said investigators are likely looking for other clues that could point them in the right direction, clues like tire tracks at the scene, dirt that could be on the victim's shoes that doesn't match the dirt there, and even pollen that might have collected on the victim's clothing before he was dumped in the spot where they found him.
"Different areas of the country, even different areas of the state, even different areas within a county have different pollen...what we call 'assemblages'," said Brendley.
Any sort of tattoo or other markings are also good clues.
However, investigators can't start filling in the blanks or tracking down the killer until they know who the victim is.
"Everybody thinks you can solve a case in about a day. And it's really good old-fashioned police work and it takes time and it takes perseverance," said Brendley.
The sheriff's office has not yet revealed whether the victim had been shot, but Brendley said if he was, they're likely looking at the pattern the bullet or bullets made in his clothing to figure out what kind of weapon was used.
If you recognize the man in the drawing, you're asked to contact the Alamance County Sheriff's Office at 336-570-6300 begin_of_the_skype_highlighting 336-570-6300 end_of_the_skype_highlighting.
WFMY News 2