Exclusive: Diena Thompson, Mother of Murdered Somer Thompson: 'I Want [Killer] to Die'

Diena Thompson, mother of murdered 7-year-old Somer Thompson, said she wants her daughter's killer "to die."

"Why? Give me your best excuse, your best reason as to why you had to do this," Thompson told ABC News in an exclusive interview that aired today on "Good Morning America." "I want them to die. I want them to get the death penalty. I have to be the voice for Somer."

The emotional interview took place just days before police named a former neighbor of the Thompson's a person of interest in the girl's death on Thursday. Jarred Harrell, 24, was arrested on 29 unrelated charges of possession of child pornography.

"We are also naming Harrell a person of interest in connection with the abduction and murder of Somer Thompson," Florida's Clay County Sheriff Rick Beseler said Thursday. Beseler would not comment further on Harrell's connection to Thompson, "as that would require I comment on evidence in an ongoing investigation," he said.

VIDEO: Closing In on Somer Thompsons KillerPlay

The term "person of interest" has no legal ramifications and police have not named Harrell as a suspect. Harrell's $1 million bond was likely due to the number of counts filed.

Somer's body was found in a Georgia landfill two days after she went missing Oct. 19, 2009. The day she disappeared, the little girl was walking to her Jacksonville, Fla., home from school with her older sister Abby and twin brother Samuel. Somer was last seen in front of a vacant house on a block she walked every day.

Despite following up on thousands of leads since Somer's disappearance, police have yet to name a suspect in the case.

Thompson, however, is determined to find her daughter's killer and said she can't wait to meet him or her face to face.

"I feel like it'll give me some more closure because I still blame myself, you know? What if I did this?" she said. "And instead of looking in the mirror and blaming myself, I'm going to have a picture of someone else to blame. I want to see this person's face. I can't wait to meet him face to face."

Thompson said she wants to know everything about how her daughter died.

"I was there when she was born and I should know, how she left," she said. "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."

Click here to read a transcript of the interview.

Person of Interest Arrested on Unrelated Child Porn Charges

Harrell was arrested "without incident" on 29 unrelated counts of possession of child pornography in Meridian, Miss., police said.

According to arresting documents, a cluster of child pornography images and video was found on several CDs and a computer Harrell used when he lived with roommates at a home in Orange Park, Fla., in August. The computer, which had a filed called "Toddler Insertion," held "a large amount of child erotica and also child pornography," according to the documents.

The roommates, who discovered the files, turned the computer over to the Jacksonville Sheriff's Office on Aug. 10, two months before Thompson disappeared.

Diena Thompson: Killer Would Be 'Lucky' To Be Caught By Cops

In early November, Thompson told "Good Morning America" her daughter's killer would be "lucky" if the cops caught him or her before she did.

"I can't imagine them not catching him," Thompson said then. "That's my scariest ... I feel like there's a piece of broken glass in front of me. And I've got all the pieces to the broken glass except for this one, huge piece and that's to catch the monster who did this."

Thompson described Somer as a beautiful 7-year-old who always wanted to help, wanted to make people feel better.

"She just always wanted everybody to be happy with her. ... So sweet. Hugged everybody," she said. Somer routinely hugged the crossing guards she met on her route home from school.

Thompson worried then that the killer may still be in the community.

"I've thought, 'Please don't let it be one of these people that's come around and hugged me and said how sorry they were.' I've thought, 'I wonder -- when we were doing the candlelight vigils if -- if he was out there," she said.

And if it turns out to be someone she knew?

"God have mercy on their soul. And they better be lucky that the Clay County Sheriff's Office is gonna get to 'em before I can."

Visit www.rememberingsomer.com for more information on the reward fund and family relief fund.

Police have asked that if you have any information about this case, contact the Clay County Sheriffs Department in Jacksonville, Fla. at (877) 227 - 6911 or the FBI.