SALT LAKE CITY (AP) — The city's police chief said Tuesday detectives are refocusing their investigation into the disappearance of Elizabeth Smart on those who know the 14-year-old girl, and vowed to the unidentified suspect: "We are going to get you."

"If you've got Elizabeth, you'd better release her now," Chief Rick Dinse told reporters on the seventh day of the investigation.

Despite checking out hundreds of tips, police have not been able to focus on any particular suspect, he said.

"We believe that it is possible that we have already talked to, or will soon talk to, the suspect that is responsible for this crime," he said. "My caution to this suspect, if he is listening, is, 'We are going to get you."'

Investigators spent several hours in the Smart home early Tuesday, searching for clues to the girl's June 5 disappearance.

Investigators are now focusing on someone who had access to the neighborhood or the house, although not necessarily a family member, Dinse said.

"We don't have an identified suspect, but we do have some analysis of what this suspect is like," he said. "While we have not located Elizabeth or identified a clear suspect, we have made progress."

Police said they have ruled out the possibility that the girl staged her own abduction and was a runaway.

So far, police have received 6,000 leads, of which 600 were worthy of followup. Half of those have been cleared.

Ed Smart, Elizabeth's father, submitted to a polygraph test on Sunday. The test is being evaluated by the FBI. Police would not say what questions were asked and a family spokesman did not know whether Smart had an attorney present during the questioning.

"It's just one of the tools we've been using to further the investigation," police Capt. Scott Atkinson said. "We're looking at every possible angle."

In a statement released Monday evening, Smart said, "When asked by law enforcement I fully cooperated because I have nothing to hide. We are doing everything in our power to bring back Elizabeth."

Police also have re-interviewed 9-year-old Mary Katherine Smart about the crime. She previously told investigators that a gunman came into the bedroom she shared with her older sister and forced her to go with him.

"Her story was consistent and we did learn some things about the suspect we didn't know before," Dinse said.

As to whether Elizabeth knew her abductor, Dinse said, "That is a possibility, and I'm not going to comment beyond that."

The volunteer search through the city and mountain foothills was tapering off. On the first day of the search, 1,200 people volunteered to find Elizabeth. By Tuesday morning that number had dwindled to 200.

But the search wass expanding into other areas. Tom Smart, one of Elizabeth's uncles, asked for 40 or 50 all-terrain vehicle owners to help search the West Desert area of Utah. Chris Thomas, a spokesman for the family, said 55 ATV owners turned out, each searching a 25 square mile area.