FORT WORTH, Texas — DEVELOPING — A Tarrant County Sheriff’s Office deputy has died after an incident in downtown Fort Worth on Friday night.

The deputy, identified as 19-year veteran Sgt. Keith Shepherd, had taken a lunch break and failed to return to his assignment around 7 p.m. to 7:30 p.m., according to Tarrant County Sheriff Bill Waybourn. A call for assistance went out around 9:27 p.m. after Shepherd was found inside his personal vehicle in the employee parking structure by fellow deputies.

One of those deputies reported Shepherd may have been shot due to the extent of his injuries — prompting a massive law enforcement response and investigation.

In a press conference after Shepherd was found deceased and identified, Waybourn reported Shepherd was found with blood inside and outside his vehicle as investigators were working to determine what exactly happened.

Throughout the course of the investigation, police determined it was likely not a gunshot wound that Shephered suffered. After an autopsy, the Tarrant County Medical Examiner's Office said Shepherd sustained injuries likely the result of a fall and suffered a pulmonary embolism.

The Fort Worth Police Department is leading the investigation into the incident.

"Our homicide unit is still investigating this matter to ensure all evidence can provide definitive information," stated Fort Worth Police Department Sergeant Chris Daniels.

Shepherd was transported to Harris Methodist Hospital in Fort Worth, Texas, where he was pronounced deceased.

Waybourn says Shepherd had a great reputation at the department, was a strong leader, and a loving husband and father.

This article has been updated from its original.