Investigators have sworn statements from witnesses who saw Tennessee nursing student Holly Bobo alive and in the presence of the two suspects after she was kidnapped, the Tennessee Bureau of Investigation said.
Authorities announced Tuesday that a second man, 39-year-old Jason Wayne Autry, has been charged with aggravated kidnapping and felony first-degree murder in the case of Bobo, who was abducted from her rural Tennessee home in April 2011. Zachary Adams, 29, was first to be indicted on the same charges in March.
Witnesses told authorities that the Autry and Adams, who are long-time friends, were seen with Bobo, who was still alive, after the kidnapping, according to the TBI.
Mark Gwyn, director of the Tennessee Bureau of Investigation, and District Attorney General Hansel McCadams also announced Tuesday that Adams faces an additional charge of coercion.
The Jackson Sun reported that Zachary Adams' brother, John Dylan Adams, saw Zachary Adams with Bobo after the kidnapping.
Zachary Adams is currently being held in the Chester County Jail without bond on unrelated charges.
According to an affidavit from a TBI agent, which the newspaper obtained, Zachary Adams asked another inmate to pass a message to his brother, who was being held at another county jail.
According to the warrant, Adams asked the inmate to, "Tell my brother he is the one who started this (expletive) and if he don't shut his mouth he will be in the hole beside her," the paper reported.
Bobo, a nursing student at the University of Tennessee at Martin, was last seen at her home in Parsons on April 13, 2011, by her older brother, who reported seeing her being taken into the woods by an unidentified man dressed in camouflage.
Bobo's brother, Clint, who was 25 at the time, said he initially thought she was being taken into the woods by her boyfriend, but grew concerned when he saw the man's arm holding onto his sister. He called his mother, who then contacted 911.
A small amount of blood was found in the family's carport, where Holly was believed taken from while on her way to school, police sources told FoxNews.com at the time of her disappearance. Despite extensive searches that included bloodhounds and high-resolution underwater imaging, authorities found no trace of the 20-year-old woman, who is presumed dead.
Authorities said at Tuesday's press conference that they expect more individuals to be charged in the case.
"We believe there are individuals out there that have information, possible involvement," Gwyn said. "Those individuals know who they are, and I’m sure they’re watching, and they can expect us on their doorstep soon."
According to the Jackson Sun, prosecutors plan to indict Shayne Kyle Austin, who had previously been granted immunity in exchange for his cooperation.
Josh DeVine, a TBI spokesman, would not confirm that report to FoxNews.com, saying in an e-mail, "We're continuing to investigate the case and have not ruled out the possibility of other people being involved in the disappearance and murder of Holly Bobo."
"That being said, we are not able to discuss or confirm specific names other than those we've previously named as those indicted and now facing charges," DeVine said.
On Tuesday, investigators said Bobo's body has not been recovered but stressed that finding her remains was a chief priority.
"We believe they [Bobo's family] deserve to know where their daughter’s body is," Gwyn said.
FoxNews.com's Cristina Corbin contributed to this report.