Is there enough evidence to convict Holly Bobo's accused killer? A trial six years in the making finally begins next month, and Zach Adams stands alone.

He is the focus of the prosecution. He is the prime suspect -- the one they will first seek to convict and then execute for the murder of Holly Bobo.

"The state has been very clear in their discussions with me that there is no DNA that links Holly Bobo to Zachary Adams," said Jennifer Thompson, Adams' lawyer.

The TBI did recover Bobo's remains, but Thompson said forensic testing came up empty.

"So there's no DNA that matches. The state told you that? Yes, and I'm comfortable that's accurate," said Thompson.

So, without strong physical evidence like DNA what will prosecutors depend on to convict?

"At this point it may be a circumstantial case with no direct evidence linking Adams to the murder of Bobo," said NewsChannel 5 legal analyst Nick Leonardo.

But he said that doesn't mean you can't get a conviction for first degree murder.

"The state will tout we don't have DNA, but we do have witnesses," said Leonardo.

The prosecution has not yet released a witness list, but there are two who figure to be near the top. First, is Jason Autry.

"I'm a drug addict and a thief. Are you a killer? No sir. By no means, I'm not a killer," said Autry back in 2014.

He is, however, also charged with Bobo's murder. Yet, by all indications Autry's cut a deal to testify against Adams.

The other key witness is this man: Benjamin Lee Hendricks. He shared a cell with Adams in the Williamson county jail.

Hendricks sent a letter, unsolicited, to NewsChannel 5 outlining graphic conversations.

He said Adams admitted he, his brother Dylan and Autry sexually assault Bobo before killing her. "Then they dumped her body by some woods close to Zack's house."

It's compelling, but it's important to note that both Autry and Hendricks are or were inmates and both have credibility problems.

"It comes down to whether or not you believe those people," said Leonardo.

Leonardo said the prosecution will need more than just witness testimony. What else is there?

Well there's this: Adams allegedly wore a pair of green "Crocs. Investigators recovered this "Croc" footwear print lifted from the carport at Bobo's home where she was abducted six years ago.

Was it left by Adams? What will the jury believe?

The trial begins April 3. A hearing is scheduled for this Wednesday to hear motions in the Bobo case. Among them, another request to delay the trial.