When Citrus County (search) sheriff's investigators were trying to find all registered sex offenders in the area while looking for Jessica Lunsford in February, they couldn't locate John Evander Couey, the man later charged with killing the 9-year-old girl.

But four months earlier, state law enforcement officials told the sheriff's office in a letter to verify where Couey lived because he didn't respond to a letter sent to his address listed in Florida's sex offender database, which could have led to his arrest, The Palm Beach Post reported Saturday.

Couey's listed address in the database was his home about 2 miles from Jessica's in Homosassa (search). But he never told state officials that he often stayed at his half-sister's house, which could be seen from the Lunsfords' home 150 yards away. Jessica's body was found buried near the half-sister's house last month.

Sheriff's spokeswoman Gail Tierney said no one in her office recalls receiving the Nov. 15 letter from the Florida Department of Law Enforcement (search). She said her office was still investigating what happened to the letter, which she said was sent to the office's old address.

The information contained in the letter was also available to sheriff's offices in an online database, FDLE spokeswoman Kristen Perezluha said.

When asked whether checking up on Couey after the letter could have prevented Jessica's abduction from her bedroom Feb. 23, Tierney said that was possible.

"But I think that it is pretty speculative on our part," she said Saturday.

FDLE Commissioner Guy Tunnell sent letters to Citrus County Sheriff Jeff Dawsy and other officials as part of an annual mailing concerning sexual offenders and predators. Couey was on a list of 58 sexual predators or offenders in Citrus County.

"Addresses for these offenders and predators require verification at this time. Address verifications on these subjects may be more than 1 year overdue," the letter to Dawsy said.

Sexual offenders are required to notify officials within 48 hours of changing their address. Violators can be arrested on a felony charge.

Couey, 46, verified his address as required by state law early in July, but he failed to sign and return a notice sent July 30 to the same address, causing him to end up on the missing list, Perezluha said.

FDLE is responsible for maintaining the sexual offender and predator database but is not required to follow up after the mailings to make sure the files are updated, department spokesman Tom Berlinger said.

Couey was arrested last month in Augusta, Ga., on a charge of failing to tell officials that he had moved from his home. Prosecutors said Couey later admitted killing Jessica and told them where to find her body. He has pleaded not guilty to charges including capital murder.