PALM BEACH GARDENS, Fla. -

Gustavo Enamorado Dubon was charged last year in one of the grisliest murders in recent memory -- the case of Coral Springs businessman Francisco Cuevas, whose head and other body parts were found in a steel box on Beeline Highway in Palm Beach Gardens.

Dubon, 23, who would have been 16 at the time of the killing, confessed to the crime and remains jailed on kidnapping and first-degree murder charges despite the fact that Coral Springs detectives who worked the case -- David Young and Brian Koenig -- have said they don't believe Dubon was actually involved in the crime.

"Brian and I are convinced that Dubon is innocent," said Young. "(We have) serious, serious serious doubts that Dubon had anything to do with this."

"I don't think he’s the guy," said Koenig.

The jarring words were captured on an audiotape made in April 2013, four months after Dubon was indicted based on their case.

The conversation among the detectives came after a taped interview of unrelated auto theft suspect. When the interview was over, Young forgot to take off his microphone and the tape kept rolling nearly an hour. Somehow it went unnoticed and the audiotape was sent out by the state attorney's office and went out to discovery to Fort Lauderdale attorney Tara Intriago, lawyer for the auto theft suspect.

The audio follows Young to the bathroom, where he speaks with other detectives, and then into a meeting with Koenig and his supervisor, Sgt. Ryan Gallagher, during which they discuss their believe that Dubon gave a false confession.

"I've been doing this for 20 years and I've never seen anything like it," said Intriago. "I was in shock. ... They're convinced they have the wrong guy."

Dubon became part of the case after he watched an extensive news piece on the case on Univision's "Aqui y Ahora" show while living in New Orleans. He anonymously contacted detectives in Palm Beach Gardens, who determined who he was.

"We talked with him and he was uncooperative," said Palm Beach Gardens police Detective John Boyle. "We found him unhelpful."

But the mother of victim Cuevas, Margarita Goedeke, convinced the police department to allow her to speak with Dubon, who was facing deportation back to his native Honduras. She met Dubon face to face in New Orleans and then spent numerous hours with Dubon on the phone, according to the detectives, who said on the tape they suspect he simply pieced together the facts he gleaned from the Univision piece and from the victim's family to form his own story about the homicide.

"They could have fed him the information," said Young. "Every detail he's given us has already been out there and none of the ones that not been exposed did he give us. It was like a copy and paste of something they would say."

Young noted that Dubon couldn't show on a map where the steel box was, which contained the victim's head, foot and other body parts.

"He didn't put the red X on the map where the head was found," said Young.

Dubon claimed the body had been dumped in a nearby lake and the city of Coral Springs spent $30,000 for excavation and draining to find it to no avail.

"He doesn't know where the body is," said Young. "We don't know anything about the body."

The motive for the false confession, Young posited, was that he wanted to keep from being deported back to the Honduras by the federal government. It's a theory that Dubon's lawyer, Anne LeMaster, said aligns with the defense in the case, along with Dubon's hope of snaring the $20,000 reward for finding the killers.

"Here, Dubon wanted to get from here to here, just to get from here to be able to be in the United States with his soon-to-be wife and child," said Young. "He wants to either stay in the country or become a hero."

Dubon's involvement in the crime evolved as he spoke with family members and detectives from simply having knowledge about the crime to being directly involved in it.

Gallagher said on the tape that Dubon claimed to have welded the steel box shut and claimed a co-defendant had also been killed in the aftermath of the crime.

Investigators and prosecutors said they never believed Dubon was the prime suspect and have said they are searching for other suspected killers in the case.

Suspicion has fallen on Cuevas' business partner in his Pompano Beach steel fabrication business, Hagen Christ, who had withdrawn large amounts of cash from Cuevas' bank accounts, according to published reports.

Christ has not been charged in connection to the case.

Another concern in the case, according to the detectives on the tape, is that Dubon has an alibi. His relatives said he was in Honduras at the time of the killing. LeMaster, said she has obtained video evidence that Dubon attended a cousin's wedding that support that claim.

"If we could find anything that put him in the country ..." said Koenig on the tape.

In addition to all the other concerns, both detectives said they believe Dubon may have mental health problems.

"I talked to a schoolmate of his who said (Dubon) got hit with a piece of corrugated metal in the head and he hasn't been the same," said Young.

"I think he's f---ing mentally ill," said Koenig. "I think he's a f---ed-up dude."

Faced with the belief that the murder suspect is innocent, what will the police and the prosecutor do?

Find out Tuesday night.