The suspect in a 2009 shooting spree at a downtown Orlando office building was reportedly found dead in a protective custody cell at Columbia Correctional Institution.
Authorities said Jason Rodriguez, 46, who suffered from mental illness, was found unresponsive Tuesday morning.
Rodriguez was in confinement because his mother was worried her son's life had been threatened.
The Florida Department of Corrections issued a statement Tuesday:
"In the morning hours of Tuesday, April 5, inmate Jason Rodriguez (X84347) died while incarcerated at Columbia Correctional Institution - Annex. In the event of an inmate death, the medical examiner will determine the cause of death. The Florida Department of Law Enforcement was notified and has become the lead investigatory authority in this case. The Florida Department of Corrections (FDC) Office of Inspector General (OIG) is proactively working with FDLE to provide investigatory assistance. The Department will employ all available resources to ensure that a thorough investigation is completed. As this is an open and active investigation, this is all of the information available at this time."
Rodriguez was accused of killing Otis Beckford and wounding five others at the Gateway Center. Prosecutors said he was targeting management at the firm where he was fired from in 2007.
He entered a no contest plea to second-degree murder in December 2015 after being found guilty in December 2013 of first-degree murder. Rodriguez was also found guilty on five counts of attempted murder.
The Fifth District Court of Appeal overturned the murder conviction of Rodriguez in August 2015 and ordered a new trial for Rodriguez.