(CNN) Cory Patterson, the Mississippi man charged with stealing a plane and threatening to crash it into a Walmart in September, died Monday while in federal custody, according to his attorney, Tony Farese and information from the Federal Bureau of Prisons.
Patterson, 29, was at Federal Detention Center Miami in Florida when he was found unresponsive at around 1:20 p.m. on Monday, according to a news release from the Bureau of Prisons. Staff at the prison and responding EMS personnel attempted life-saving measures, but he was pronounced dead at the facility, according to BOP.
Patterson, who was not a licensed pilot, had pleaded not guilty to charges of grand larceny and making terroristic threats, CNN has previously reported. He was accused a stealing a twin-engine aircraft from a regional airport in Tupelo, Mississippi, and calling 911 to say he was going to crash into a local Walmart.
The threat caused chaos in the city as officials rushed to evacuate the store and its surrounding areas and close down major streets, police said. After Tupelo Police negotiators attempted to guide Patterson to land at the airport, he eventually touched back down in a field and was arrested.
Patterson was sent to the Miami detention center to receive psychological evaluation, which Farese requested in September, the lawyer told CNN.
Patterson arrived in Miami on November 10 and died four days later, according to BOP, which did not provide a cause of death. Farese said Patterson died by suicide.
The Federal Bureau of Investigation and US Marshals Service were notified of the death. The Miami-Dade Medical Examiner's Office told CNN Patterson's death is still under investigation.
Farese said the BOP and FBI would be investigating, as is protocol. A spokesperson for the FBI, however, neither confirmed nor denied the existence of an investigation into the case but acknowledged the agency investigates in custody deaths of federal inmates as a practice.
Farese said he is working with the BOP to return Patterson's body home to his family in the Tupelo area.