( CNN ) -- A former chemist in a Florida crime lab was arrested Tuesday on charges of selling stolen drug evidence that had been switched with over-the-counter medicine , authorities said . Joseph Graves is accused of grand theft , 12 counts of tampering with evidence and nine counts of drug trafficking , the Florida Department of Law Enforcement said in a written statement . Authorities say he replaced prescription drugs held as evidence with medicine that could be bought without a prescription . `` The actions of Joseph Graves are disgraceful , '' Florida Department of Law Enforcement commissioner Gerald Bailey said . Officials have said the disclosure could affect some drug convictions in dozens of Florida counties . Graves was arrested at the Escambia County Jail and a judge set bail at $ 290,000 . Additional charges are possible , the news release said . Gretl Plessinger , chief spokeswoman for the Florida Department of Law Enforcement , told CNN on Saturday that the chemist worked 2,600 cases for 80 law enforcement agencies in 35 Florida counties and 12 judicial circuits over the past eight years . Plessinger pointed out that it was 1 % of the volume of evidence handled by the lab . The investigation began last week when investigators discovered missing prescription pain pills from the evidence room at the Escambia County sheriff 's office , authorities said . The missing prescription drugs had been replaced with over-the-counter medications . On Thursday , investigators determined that each case with missing prescription drugs had been analyzed by Graves , and authorities opened a criminal investigation . Florida Attorney General Pam Bondi said her office would assist in the investigation . `` Our battle against prescription drug abuse in Florida has been very successful over the last three years , and I will not tolerate any actions that compromise our continued success in ridding our state of this problem , '' Bondi said in a statement .
Joseph Graves worked at a drug lab that tested drugs in cases . Authorities believe he switched the drugs with pills that were n't and sold the stolen pills . His bail was set at $ 290,000 . Officials are concerned this could mean some previous convictions will be overturned .