A fingerprint mix-up at the Georgia Bureau of Investigation Crime Lab may have linked the wrong man to a 2005 Dallas murder, authorities said.

And the error could unravel the 3-year-old murder case, authorities said.

"That fingerprint was a key piece of evidence that placed the suspect, Dexter Presnell, on the scene," Paulding County Sheriff's spokesman Brandon Gurley said.

Fingerprints lifted from the scene of the October 2005 murder of Regan Wheeler identified Presnell.

But GBI officials said a Crime Lab print examiner used the wrong prints.

"It's an error that cannot be tolerated," GBI spokesman John Bankhead said. "Everybody feels terrible about it. Obviously the person who made the mistake, his supervisor, really the entire GBI."

Wheeler's wife declined comment, but his father-in-law, Paul Dunagan, was disappointed.

"It hurts me that this is happening," Dunagan said.

Wheeler was found shot to death after returning home to find a burglar in his home.

Presnell was arrested in October 2006, and has been held without bond in the Paulding County Jail in Dallas since then.

A fingerprint lifted from the scene was to be compared to the suspect's prints, but the examiner mistakenly pulled a digital image onto his computer of a print from Wheeler's daughter who lived at the house.

The print was similar to Presnell's, Bankhead said.

"The problem, when they come up on screen, there's nothing to ID who they belong to," he said. "They were a match, but not the suspect's prints."

Double checking his work later, the examiner found that the fingerprint lifted from the crime scene didn't match Presnell's print as initially believed, but rather the prints of Wheeler's daughter.

While circumstantial evidence also connected Presnell to the case, the fingerprints were the lynch pin, Paulding County district attorney Drew Lane said.

"The other evidence is insufficient to prove the case of murder against Mr. Presnell beyond a reasonable doubt," Lane said.

Lane's office requested Tuesday that the murder case be dropped.

He said the setback doesn't automatically make Presnell innocent, however.

"The fact that we have a [discontinuance] of the case is not an exoneration of Mr. Presnell," Lane said. "This case is still under investigation."

Paulding County Sheriff's office forwarded the case to Atlanta Crime Stoppers, with an additional $2,000 reward.

"We've got leads, but not enough to make an arrest," Gurley said.

Lane said the error could have been worse.

"I do appreciate that the GBI crime lab announced this error prior to trial," he said. "It's much better than finding the error or having the error pointed out during a trial or after a trial."

The GBI is making changes to prevent the error from happening again, Bankhead said.