TRANSCRIPT: Diena Thompson on Catching Daughter's Killer

Feb. 12, 2010— -- On Thursday, police named a person of interest in connection with death of 7-year-old Somer Thompson, Diena Thompson's daughter. Jarred Harrell, a former neighbor of Thompsons, was arrested on 29 counts of possession of child pornography, Clay County Sheriff Rick Beseler said Thursday.

Beseler would not comment further on Harrell's connection with the girl.

Click here to read ABC News' full report on Harrell's arrest.

Thompson vanished on Oct. 19 while walking to her Jacksonville, Fla., home from school with her two siblings. Investigators searched for two days and sorted through more than 225 tons of garbage at a landfill some 50 miles away across the state line in Georgia, where they found her body.

Days before Harrell was arrested, Deana Thompson sat down with "20/20" anchor and chief law and justice correspondent Chris Cuomo for an emotional interview.

Part of that interview aired Feb. 12 on "Good Morning America" and "Nightline." The transcripts are below:

CHRIS CUOMO: The idea of catching the bad guy, the monster who is still out there. What happens when that happens?

DIENA THOMPSON: I feel like it'll give me some more closure because I still blame myself, you know? What if I did this? Or what if this could have been done and instead of looking in the mirror and blaming myself, I'm going to have a picture of someone else to blame. So I just, I want to see this person's face. I, I can't wait to meet him face to face.

CHRIS CUOMO: What would you say?

DIENA THOMPSON: Why? Give me your best excuse, your best reason as to why you had to do this.

CHRIS CUOMO: ...Do you care what happens to whoever did this?

DIENA THOMPSON: I want them to die. I want them to get the death penalty…I've got to be the voice for Somer.

CHRIS CUOMO : When…when the investigation ends, and it ends, hopefully, in the arrest of the right person, do you then want to know everything you don't know right now?

DIENA THOMPSON: Yes.

CHRIS CUOMO: Yes. Why.

DIENA THOMPSON : 'Cause I-I was there when she was born and I should know, how she left.

CHRIS CUOMO: What good do you think it'll do for your head, to hear what could be, not something that's pleasant to hear.

DIENA THOMPSON: Because I've built up so many scenarios in my head, that I honestly don't feel like anything they could tell me, could be any worse than what I've already…made up in my head.

CHRIS CUOMO : What is the hardest part in all of this emotionally for you to deal with.

DIENA THOMPSON: Knowing that I'm never gonna…while I'm on this earth, ever gonna be able to hold her, touch her, have-smell her, you know, your children, they just have this smell about them. Each one unique to itself, and, just knowing that I'm never gonna get to see, you know, her look up at me and…smile.

DIENA THOMPSON: She—you know, she had problems like actually with her speech like, you know, "yittle" instead of "little."

CHRIS CUOMO: You had a nickname for Somer. Grace.

DIENA THOMPSON: Yeah.

CHRIS CUOMO: Why?

DIENA THOMPSON: because she was so clutzy. I mean, she could not walk and chew bubble gum at the same time, but she loved to dance. She wanted to be a ballerina.

CHRIS CUOMO :That night…what are you telling yourself.

DIENA THOMPSON: I'm never gonna see her again.

CHRIS CUOMO: You were that confident that that's—

DIENA THOMPSON: I—I can't explain it, but, I just knew, that she was gone.

DIENA THOMPSON: All I remember is losing it. I mean, literally losing it. Screaming and, later on neighbors telling me they could hear me, the shrills across the street. And they, then…knew, 'cause I think they didn't say on the news until the next day, that they confirmed it to the public, but, of course, being the—being the mother, they called and told me.

CHRIS CUOMO: You want to know all of it. You want to know what happened to Somer.

DIENA THOMPSON: I do.

CHRIS CUOMO : No matter what the detail, no matter what that involves.

DIENA THOMPSON: I think that the picture I have drawn in my mind of what I think happened can't be any worse than what actually happened cause your mind will play tricks on you...