TALLAHASSEE, Fla. (AP) -- Prison officials say a convicted sex offender on death row for kidnapping, raping and burying a Florida girl alive has died of natural causes.

After John Evander Couey abducted 9-year-old Jessica Lunsford, whose mother lived in Morrow, Ohio, from her bedroom in 2005, many states passed laws named after her that impose restrictions on sex offenders.

Department of Corrections spokeswoman Gretl Plessinger says Couey died of natural causes Wednesday at a Jacksonville hospital. The 51-year-old had been sentenced to death in 2007.

Plessinger says Couey had been ill for some time. She declined to provide any specifics, citing a federal law protecting the privacy of hospital patients.