Agents with the Florida Department of Law Enforcement and the Escambia County Sheriff's Office arrested former Pensacola crime laboratory chemist Joseph Graves.
Graves faces charges of grand theft, 12 counts of tampering with or fabricating physical evidence and nine counts of trafficking in illegal drugs.
Investigators believe Graves, while processing drug cases, replaced prescription pain pills with over-the-counter medications.
"The actions of Joseph Graves are disgraceful. FDLE is working with state attorney's offices statewide to ensure he is held accountable for his actions," said FDLE Commissioner Gerald Bailey.
Graves was arrested this evening at the Escambia County Jail.
FDLE teams are inspecting evidence from all cases handled by Graves dating back to 2006 to confirm potentially compromised cases.
FDLE says Graves worked nearly 2,600 cases for 80 law enforcement agencies spanning 35 counties and 12 judicial circuits.
The Office of the State Attorney, 1st Judicial Circuit William Eddins will prosecute this case.
The investigation is ongoing. Additional charges are possible.