Monday night, we told you about Martin Priest.
He's the man now charged with Tammy Sue Rothganger's murder.
The Eldon teenager was just 15 when she disappeared in 1984 and she hasn't been seen since.
Priest was her mother's boyfriend.
Investigators believe he could be responsible for at least four other deaths.
We hear from the family of Katrina Cheely, one of his alleged victims, as we continue to investigate "A Suspected Serial Killer".
Martin Priest was a friend of the Cheely family in Wichita, Kansas.
"He was ok," Linda said. "He became friends with all of us and we all hung out together and he used to come to my house for coffee with my friends and all that."
Linda, asked us to conceal her identity.
She's the mother of five, three boys and two girls.
Katrina was her oldest.
"She was a very, very pretty girl and she had a personality that was unbelievable," Linda said. "She was a lot of fun and she could get you to laugh on your worst day."
In November of 1984, Linda says 15 year old Katrina was running late for school and Priest said he'd take her.
When Katrina didn't come home from school that day, Linda knew something was wrong.
"I was just devastated, devastated," Linda said. "Because that's not Katrina. Katrina just doesn't disappear and not say where she's going. She always told me where she was going or she'd make a phone call and say 'mom, I'm at a friend's and I'll be home in a little while.'"
Linda says she immediately called Priest.
"I said 'what did you do with my daughter'" Linda said. She said Marty responded with "Oh, she'll be home, she's probably just off with her friends and stuff."
Katrina's family reported her as a runaway, but always believed Priest had something to do with her disappearance.
"He was the last one seen with her and he took off and he never returned," Katrina's brother Tyrone Cheely said. "He looks evil, the way he was...I just never trusted him. Even when I was a kid I never trusted him, I tried to stay away from him."
In February of 1985, an officer knocked on Linda's door.
He told her they had found the body of a girl and they needed Linda to go to the police station to see if she recognized some belongings.
"We sat in the room and he took a little envelope...put whatever was in the envelope in his hand and he said 'now I'm going to show you something and I want to see if you can identify it,'" Linda recalled. "He opened up his hand and my heart hit the floor. I was just devastated. I said 'that's my daughter's ring, where did you get that?' the detective wouldn't answer me the first time. By this time, I'm getting furious, 'where did you get that ring?' he still didn't answer me. The third time I stood up and pounded my fist on the table and I said 'where did you get that ring? That belongs to my daughter' and right then and there, they knew it was my daughters and they had found my daughter's body."
Linda was in shock.
"I didn't know who my own kids were, I didn't know who my husband was, I was just so devastated," Linda said.
Priest was eventually charged with Katrina's murder but the jury found him not guilty.
"Frustratingyou talk about frustrating, you just wonder what these people were thinking," Former Sedgwick County Sheriff's investigator Danny Bardezbain said. "And then to know everything we knew about him when Katrina went to trial and then the jury walks him, then when you tell him things, their frustration multiplies your frustration."
The verdict didn't change what the Cheely family believed.
"He took my sister away," Tyrone said. "I think about her 24/7, 365 days a year. What she could have done, what she would be like. She was my big sister. She was my role model."
"I have nights where I can't get to sleep at all," Linda said. "I still hear her, I still hear her voice, I still see her face. I wish this nightmare would just go away and I could wake up and say everything's going to be ok but it's not. It will never be ok."
On January 4, 2016 Martin Priest was charged with capital murder in Miller County in the disappearance of Tammy Sue Rothganger.
Priest currently is in prison in Kansas for another murder there.
In August, he comes up for parole.
KRCG 13 contacted Martin Priest but did not get a response.
According to court records, Priest does not have an attorney for the capital murder charge he's facing in connection to Tammy's death.
In a statement to KRCG 13, Miller County Prosecutor, Benjamin Winfrey said:
"I cannot comment on any pending case under both Missouri law and the professional rules of ethics. Specifically, the law states that a prosecutor should not make any extra-judicial comment. As such, any comment outside of a court proceeding is not allowed."