UPDATE: Friday, Channel 3 learned Bill Hawk faces a felony charge in Greene County, for allegedly being a felon in possession of a firearm.
Hawk has pleaded not guilty in Hamilton County, the trial starts April 5th.
PREVIOUS STORY: According to our NBC affiliate WCYB, crews exhumed Johnny "Mack" Salyer's body from his grave site. New technology and advancements in the process will allow them to examine the body and get more information about the body, said Russell County Commonwealth attorney, Brian Patton.
Salyer's body was taken to the University of Tennessee Forensic Anthropology Center for another autopsy.
Billy Hawk's trial is set for the first week of April in 2016.
PREVIOUS STORY: Channel 3 is learning more about the man arrested in a Hamilton County cold case that went unsolved for 34 years. Billy Hawk, 61, is charged with first-degree murder in the 1981 death of Johnny "Mack" Salyer.
It's the fourth case to be cleared by the District Attorney's Cold Case Unit since it was formed last year.
Salyer, 27, was found dead in June 1981. He was stuffed inside a barrel that was tossed in the Tennessee River.
Investigators suspected Billy Hawk all along, but he was never arrested -- until Tuesday morning.
Hawk has hired Cleveland attorney Jimmy Logan and will make his first court appearance on Friday.
WRCB uncovered court documents outlining Hawk's criminal past and time spent in federal prison. He was previously convicted of drug charges, domestic violence against an ex-wife and pleaded guilty to federal gun charges.
Court documents show that in 2004, Hawk was illegally in possession of over 100 firearms and more than 10,000 rounds of ammunition. He served 20 months in federal prison.
If convicted of Salyer's murder, he could spend the rest of his life behind bars.
"There was a lot of good information developed 34 years ago," said investigator Mike Mathis.
While Salyer's murder case seemed solid case back in 1981, it took fresh eyes -- and about 34 years -- to officially solve it.
"The big question has been, why wasn't more done? That's not what we do. We're not here to critique what someone didn't do. We do what we do," Mathis said.
While efforts turn to prosecuting Hawk's case, the Cold Case Unit isn't slowing down.
"As a general rule, we try to work three or four at a time," said District Attorney General Neal Pinkston. "There are other ones we are still actively working right now."
Anyone with information about other unsolved murder cases should call the Cold Case Unit at 423-209-7470 or e-mail firstname.lastname@example.org
UPDATE: "Every police officer, especially those who are assigned a particular case, can think back, and there are always four, five, six cases throughout your career that you constantly have in the back of your mind," said Hamilton County Sheriff Jim Hammond.
Twenty-seven-year-old Johnnie "Mack" Salyer's unsolved murder is a case Hammond has been hoping to clear since June 1981. He was Chief Deputy 34 years-ago, when Salyer's body was found stuffed inside a steel barrel, floating for over a week in the Chickamauga Lake, near lakeside.
Salyer was identified by a Rolling Stones tattoo. His official cause of death was never determined, but investigators always had a hunch.
"Knew the suspect all along, knew some of his family personally," Hammond said.
On Tuesday, the cold case unit announced Salyer's case was solved, and the suspect, 61-year-old Billy Hawk of Greene County, was in custody.
Old investigative records show Hawk was an original suspect, but there wasn't enough evidence to arrest him.
"While once you may have been a scared kid, scared child, scared youth, as an adult you have a far different view," said District Attorney General Neal Pinkston.
Back in the early 80s, Salyer and Hawk were involved in the local drug scene. They were charged together for selling cocaine. But before the case could make it to trial -- Salyer, who cooperated with authorities, was killed.
Pinkston said several old witnesses finally came forward, leading to Hawk's indictment earlier this week.
"Sometimes witnesses will say something this week that they wouldn't have said at this time last year," explained Detective Bill Phillips.
This is the third cold case to be solved since renewed efforts by the DA's office in 2014.
"With hard work, it shows," said Pinkston. 'We don't give up."
Hawk was booked into the Hamilton County Jail on Tuesday afternoon. If convicted, he could face life in prison.
Anyone with information about Hamilton County cold cases should call (423) 209-7470 or e-mail email@example.com.
PREVIOUS STORY: The Hamilton County District Attorney’s Cold Case Unit has solved another homicide, and the suspect is now in custody – 34 years after the murder took place.
On Monday, the Hamilton County Grand Jury indicted William Frank “Billy” Hawk on a charge of First Degree Murder for the 1981 death of Johnny Mack Salyer .
Hawk was taken into custody on Tuesday morning in Greene County, Tennessee, by Cold Case Unit Chief Mike Mathis, a TBI Agent and a HCSO Fugitive Detective.