Homosassa, Fla. ? A registered sex offender admitted Friday that he kidnapped and killed a 9-year-old girl who disappeared from her bedroom more than three weeks ago and told police where they could find her body, authorities said.

John Evander Couey, 46, had been arrested Thursday and named a “person of interest” in Jessica Lunsford’s disappearance. He confessed to authorities after taking a lie-detector test, Citrus County Sheriff Jeff Dawsy said.

“At the end of the polygraph, he said, ‘You don’t have to tell me the results. I know what they are,'” Dawsy said. “He apologized to the investigators for wasting their time.”

Authorities cordoned off an area Friday near the trailer home of Couey’s half-sister, who lived about 150 yards from the home Jessica shared with her father and grandparents. Dawsy would not comment on what investigators were doing in the area, but said it “will take hours.” Police had yet to recover a body.

Paramedics and firefighters assisted in digging what appeared to be a pit behind the home and carried away large brown bags. It was not clear what the bags contained.

A sheriff’s spokeswoman who answered the phone at the Lunsford home Friday evening said the family declined to make any comment. Jessica’s father, Mark Lunsford, has said the family did not know Couey.

Jessica’s stepfather, Lonnie Bryant, said by telephone from Ohio that he and the girl’s mother, Angela Bryant, planned to come to Florida soon.

“I’m going through agony right now,” he said.

Jessica, a third-grader, was last seen when she went to bed in her home Feb. 23. She was discovered missing the next morning, with the door unlocked and her stuffed animal gone.

Authorities said Couey left Florida on or about March 4 after telling relatives that police would be looking for him. He was arrested in Augusta, Ga., on a probation violation for failing to notify officials he was moving, a requirement for sex offenders. He was awaiting extradition to Florida on Friday.