The results were positive. Velazquez reclassified Jackson's case from a disappearance to a homicide.
"At times, the case felt overwhelming," Velazquez recalls. "It kind of took on a life of its own, but I wasn't intimidated. I let it speak to me. I followed it."
She was motivated in part by sympathy for Jackson's mother. Velazquez and Carlson were becoming friends, and Velazquez related to "just needing to know where your child is."
And John proved a tremendous resource in her investigation. From the boy's description of his stepfather, Velazquez tracked down Michael Wolfe. He was living with a new wife in Kettering, Ohio. Velazquez found it odd that he had married Britton so quickly after meeting her, just a few months before Jackson disappeared.
Velazquez spent a year directing a flurry of phone calls, subpoenas, and interviews. In June 2004, detectives turned up the heat on Wolfe. Velazquez's partner met him in Ohio on June 17, and he began to talk.
That same day, in Florida, Velazquez went to visit John.
"What your mom has told you has not been the truth," she said, according to a transcript. "I didn't want to be the one to tell you. But as a man, you need to hear this... I wholeheartedly believe that your father was murdered. And I wholeheartedly believe that your mother has firsthand knowledge of it... Your father was murdered because of his love for you over child custody issues. Your mother never wanted to share you with him."
John's response was chillingly calm. "Oh, I do believe she's holding information," he said.
"I don't think your mom is a bad person," the detective continued. "I think [she] has some mental problems."
John didn't demur, but he doubted that his mother would provide any new information. "She thinks you're waiting for her to say something she didn't say 20 years ago," he told Velazquez. "I would hook her ass up to a polygraph."
"What will you do if your mother is arrested?" she asked.
"If she is an accessory," said John, "I'll put the cuffs on her myself."
The detective asked him to persuade his mother to meet with her that very night, after she got home. John agreed.
"She'll probably be in her nightgown... if you come to the door," he said drolly. "That'd be funny."
Before they parted, she encouraged the dogged Police Explorer.
"Work your voodoo, man," she told him. "Go do your cop thing. You are now the detective. You are empowered. Go get her."
He did. That night, Velazquez and a partner came back inside the house to talk with Britton. They had met before, six months earlier, and Britton had denied any knowledge of a crime. Velazquez pressed harder now, confident that she could use Wolfe as leverage.
She started with the facts. The bones.
"We found David's body," said Velazquez. "He's been murdered."
"Where was he at?" asked Britton.
"In a very isolated area not too far from here. I have DNA results."
"Are you sure?"
She continued. "My partner [is] out in Ohio where Mike Wolfe now lives," she told Britton, who was getting agitated. "Um, he said that... him and your dad were involved, and that you knew about it."
"I didn't know about it, no way."
"Mike is willing to take a polygraph. Are you willing to take a polygraph?"
Britton didn't answer. She was upset, focusing on the supposed role of her father, who had died in 1998. "My dad — I don't — I don't understand," she said, beginning to hyperventilate.
"The truth," said Velazquez. "That's the only thing that's important right now."
"Do you want me to make y'all some coffee or something?" interjected Britton.
"We're good, thanks." The detectives waited for an answer.
Britton broke down and was unable to speak. Still, she would maintain that she was in Tucson when David disappeared. "I was in another state. I don't know what happened," she told police. "I have to go on what the police tell me. I have to go on what the newspaper said."
The next day in Ohio, after hours of questioning and a lie-detector test, detectives asked Wolfe to put a statement in writing. Wolfe wrote that a few months before the disappearance, on a visit to Florida, he and Harry Britton had been watching John play at a park in Miramar — a park just across a lagoon from the new Walmart.