A man who killed himself before police could question him about the abduction of a 4-year-old Missouri girl was a convicted sex offender, a local official told CNN Thursday. Paul Smith, 38, died from a self-inflicted gunshot wound to the head, Lincoln County, Missouri, coroner Robert Shramek said. Smith shot himself as investigators approached him late Wednesday afternoon. He died in a hospital at 10:29 p.m., Shramek said. Smith was a convicted sex offender, according to Missouri's sex offender registry and Louisiana, Missouri, city administrator Bob Jenne. St. Louis County Police Chief Timothy Fitch told reporters Thursday that "good old-fashioned detective work" led authorities to Smith."We have plenty of evidence that Paul Smith is the suspect," Fitch said in a news conference. The girl, Alisa Maier, was found alive Tuesday night in the St. Louis suburb of Fenton, about 70 miles south of her Mississippi River hometown of Louisiana, Missouri. She was wearing different clothes than the ones she had on when she was abducted, and Fitch said they were able to trace those clothes to a particular Wal-Mart.