BIRMINGHAM, Ala. (AP) — An Alabama businessman convicted on a child sex charge died after he apparently swallowed poison following the reading of the verdict, a medical official said Tuesday.

William Thomas Moore Jr., 42, was being booked into jail in Tuscaloosa on Monday when he told officers he had swallowed a cyanide pill, said Travis Parker, emergency medical chief for the Tuscaloosa Fire and Rescue Service. Moore was dead before rescuers a few blocks away could arrive.

"Our guys said the jailer told them he said, 'I took cyanide,'" Parker said. "It was fast-acting whatever it was."

An autopsy was being performed but results were not immediately available. Parker said it was clear the man ingested something that killed him, but chemical testing was required to determine the exact substance.

Moore faced a maximum sentence of 20 years in prison on the conviction.

Joe Basgier, one of two defense lawyers who were in court with Moore, said people in the gallery reported seeing the man place something in his mouth as soon as jurors announced Monday he was guilty. Moore claimed in court to only be taking his daily medication, said Lt. Dale Phillips, commander of the area homicide unit.

After the verdict deputies handcuffed the man, who walked out of court on his own, Basgier said.

Parker said medics carry an antidote to cyanide and used it on the man without any results. Workers found nothing in the man's mouth that could have been used as a container for poison, Parker said.

"His family is in the exterminating business. We don't know if he got something from that or not," Parker said.

Moore was indicted in December 2011 and had been free on bond while awaiting trial. Moore, who police said had worked for a time with the family pest control business, was acquitted on a sodomy charge before the guilty verdict was announced.

Court records show he had a record that included arrests on drug charges and a conviction for selling drugs near a school in 1994.

Moore's death came just weeks after a Missouri man used cyanide to commit suicide in court after being convicted on a charge of molesting a 14-year-old girl.

Phillips said it could take weeks to obtain test results from a state laboratory to verify what type of substance was involved.