NASSAU COUNTY, FLORIDA — A suspect has died after a gun went off while they were in the custody of Nassau County authorities, officials report.

On Thursday at noon, deputies encountered the suspect at a Culver’s restaurant in Yulee. The individual, whose identity has not been disclosed, was wanted in Southwest Florida on charges of auto theft and was reportedly heading north.

Once apprehended, handcuffed, and seated in a patrol vehicle, the suspect managed to inflict a fatal gunshot wound on themselves with a hidden firearm, according to the sheriff’s office.

Despite efforts by Nassau County Fire Rescue to save the suspect, they did not survive the injury.

The Nassau County Sheriff’s Office communicated to First Coast News that it is unclear whether the suspect was searched or patted down prior to being placed in the patrol car. The deputy involved has not been named.

“The Florida Department of Law Enforcement (FDLE) has been notified and will conduct an independent investigation, which is standard protocol for incidents of this nature,” NCSO said in a news release. “The Nassau County Sheriff’s Office will also conduct an internal review to determine whether any policy violations occurred and will take appropriate action pending the outcome of the investigation.”

The sheriff’s office says the investigation is still in its preliminary stages, and information could change as it proceeds.

This is a developing story.