For the first time, former Clay County Sheriff Rick Beseler is releasing more details about the man now serving a life sentence for the kidnapping, rape and murder of Somer Thompson.
The 7-year-old disappeared the afternoon of Oct. 19, 2009, as she was walking home from Grove Park Elementary School in Orange Park.
Beseler is now retired and sat down with News4Jax to discuss the case, one of the most haunting of his career.
"I can't believe it's been 10 years," said Beseler as he talked about the night his chief of detectives called him to say a little girl was missing. "There was something in his voice that told me, this was the real deal."
As it turned out, Beseler's department had received specialized training to better prepare for child abduction cases.
"Immediately after taking office, I decided to take part in the Child Abduction Response Team or CART, which was being pioneered by the FBI and the Center for Missing and Exploited Children," he explained.
Beseler credits the training as the reason they were able to find Somer's body so quickly and catch her killer.
WATCH: 10 years later, detectives talk about finding Somer
As part of that training, Beseler's investigators learned about the importance of checking dumpsters in and around the area of a child's disappearance.
"Statistically speaking, the first hour since a child goes missing is the 'golden hour.' If you don't find that child within that length of time, statistically speaking, they are probably dead," Beseler said.
While they searched for Somer under the assumption that she was still alive, they had to also consider that whoever took her had already disposed of her body -- since deputies were not notified right away about the 7-year-old's disappearance.
Somer usually walked home from school with her twin brother and older sister. However, on that day, she and her sister had a disagreement and Somer ran ahead in the direction of home. When her siblings arrived home and Somer wasn't there, they assumed she was hiding. After searching themselves and calling family, her mother called 911.
As hundreds searched for Somer, dumpsters that had been emptied in the area were diverted, and the trash was searched at a landfill in Folkston, Georgia.
Three days after Somer vanished, her body was discovered among the trash taken from a dumpster behind a Clay County restaurant -- the same restaurant where her killer worked.
During our interview this week, Beseler said something that we'd never heard before about the day Somer's remains were found. The evidence that tied Somer to her killer almost slipped away.
Since Somer's body was discovered in Georgia, it was outside Beseler's jurisdiction.
"We were at the mercy of state authorities and local authorities. We were not in charge at that point. The local medical examiner had told our recovery team, ‘Don't touch the body. Don't do any testing of that body,'" explained Beseler. "But luckily, an FBI agent, Larry Myers, was there, and he said, ‘I'm going to take DNA samples anyway.' He swabbed the body at the location where she was recovered and ultimately recovered DNA -- which was pivotal in proving that Jared Harrell was a suspect. By the time the medical examiner came and recovered the body, took it to Savannah to do the examination, they found no DNA at that point."
That DNA would later become the most crucial piece of evidence in Somer's murder investigation. It took time for the DNA to be processed, so deputies did not know Jared Harrell -- who lived on the street where Somer was last seen -- was a suspect. That changed when they asked him for a DNA sample.
"He refused. We had taken hundreds of DNA samples from everyone in the community, and one person refused. In the police business, we call that a clue," Beseler said. "Ultimately, his mother convinced him to give us a DNA sample, and as soon as he did, he left town -- but not before we could put a tracker on him."
They followed the 24-year-old Harrell to Meridian, Mississippi, and watched him from morning to night.
"We were afraid he would harm another child," Beseler said.
DNA analysis can take weeks or even months, and they needed all the evidence to get a warrant. They eventually decided to arrest him. The reason: Beseler said during surveillance, investigators discovered Harrell was following girls in public places.
"That is why we approached him in a store and tapped him on the shoulder. He turned around and saw one of our Clay County deputies standing there, and the blood drained out of his face. He knew he had been caught," Beseler said.
He said he believes Harrell was probably preparing to grab another girl when he was arrested.
Harrell pleaded guilty to 7-year-old Somer Thompson's kidnapping, rape and murder. He waived all rights to an appeal.
"He will die in prison, and he will never harm another child again," Beseler said. "For that, I am thankful."
'Stranger danger' warning might not work
Somer's mother had talked to all of her children about strangers, telling her that "bad people" could use dogs to trick children. Somer loved animals.
We will never know exactly what happened in the moments before Harrell lured the young girl into his family's house, it appears that Somer was not frightened of him, at least at first.
No one reported to deputies that she was dragged into the home. Harrell told investigators she came to his front door looking for his mother's dog.
Beseler described it as, "a crime of opportunity."
"She (Somer) had a normal routine that there was a little dog that she would pet on the way home and there was a palm tree in the front yard that ended up being the home where the suspect lived and she liked to go and sit under the tree and play with the dog," he explained.
Diena Thompson said she didn't know her daughter had previously played with the dog at the house.
The day Somer was kidnapped, something was different.
"As it turned out, the dog was not there. The suspect was moving and she was looking for the dog that day, I believe," Beseler said. "We believe that as she was looking for that dog, the suspect engaged her in conversation and may have led her to believe that the dog was inside the house. We think that is why she went into the house and once the suspect had her inside, away from public view, then he was able to harm her."
WATCH: Sheriff shares how to protect your children from a sexual predator
Beseler said his first impression of Harrell was surprise.
"The first thing that struck me, he didn't look like a killer. He was overweight. He was not threatening looking at all. He didn't look like your typical killer as you would imagine from watching TV movies," Beseler said. "It made me realize that people like that can get to children because they don't seem threatening. They don't seem dangerous. … They look like your next door neighbor. They look like the kid that works at the pizza joint or the fast-food restaurant. Jared Harrell was there working at a fast-food restaurant. Those are the people that do these kinds of crimes that you don't necessarily suspect."
For decades parents have been warning their children about "stranger danger," teaching them to stay away from strangers who might hurt them. But who is a "stranger"? Do they look like a "bad person"?
Stacy Pendarvis, program director for the Monique Burr Foundation for Children, which offers classes and training to teach parents, educators and children about safety, said that the message we've taught our kids about strangers needs to change.
WATCH: Protecting your kids from predators
"We teach 'safe adult,'" she said. "The idea is that we identify people in our child's life who we know are safe. It takes away the guessing."
Another idea is create a "safe list": a short list of names of adults your children can talk to or leave with if they are not with you.
You can also create a password for your child. If an adult claims they know you and have been sent by you to pick up the child, the child can ask for the password. If the stranger doesn't know it, the child can get help from a safe adult right away.