The mother of the man recently convicted of killing and raping Tennessee nursing student Holly Bobo claims her son is innocent. She also said her other son, currently awaiting his own trial in connection with Bobo’s death, is innocent as well.

Cindy Adams sat down with ABC News’ 20/20 to talk about the high-profile case that left a 20-year-old college student deceased, wrapped in a blanket, shot in the head, and hidden for over three years. Last week, a Tennessee jury convicted Cindy’s oldest son, Zach Adams, of murdering and raping Bobo, and as she awaits for her son Dylan Adams’ trial, she wants the public to know that she feels they are both innocent.

“In my heart of hearts, I knew, I knew– I know my boys. They’re drug addicts. They’re not murderers.”

Authorities that worked the Holly Bobo case disagree. Former criminal TBI investigator Terry Dicus told ABC that the Adams brothers were brought up by tipsters almost immediately.

“They were brought up early and often. They were brought up by people that know that they’re just bad people– into drugs.”

With no hard evidence, it took years before authorities charged Zach Adams with Bobo’s murder. Bobo vanished in April 2011 as she left her home for the day in Darden, Tennessee. In Sept. 2014, authorities discovered her body after men out hunting ginseng stumbled across her remains. Even then, detectives still didn’t have enough evidences to charge the suspect. It wasn’t until Dylan Adams told authorities that his brother killed Bobo that they made an arrest.

Cindy Adams claims that her son Dylan has a “low IQ” and that detectives coerced him into a false confession.

“I was like, ‘You’re lying. Who is making you say this?’ Because you got to remember, I have asked my boys over and over and over, you know, ‘Do you know anything about Holly? Do you know anybody that knows anything about Holly?’ [I asked] because this young [woman] was missing, and I was just trying to see if possibly, you know, they knew something that could be beneficial to help find Holly.”

On Sept. 17, 2014, authorities also arrested Dylan Adams and charged him with tampering with evidence after he confessed to helping his brother dispose of items linked to Bobo. Dylan Adams was later charged with raping her.

Zach Adams was sentenced to life in prison for the rape and murder of Bobo. Dylan Adams’ trial date has not yet been scheduled. Another man charged in connection with Bobo’s disappearance, Jason Autry, received immunity for testifying against Zach Adams.

[Feature Photo: Family Handout]