UPDATED: October 2, 2018  5:48PM

DENTON (CBSDFW.COM) – Neighbors called police to report a man who had collapsed and died in the alleyway behind a house in the 3600 block of Camino Real Trail.

They told police the 23-year-old man’s face was bloodied and that he may have been shot.

Detectives said the man had recently returned from Vietnam and was ill for several weeks.

Local health authorities were contacted.

“Denton County Public Health is currently collaborating with the local authorities and the medical examiner to conduct a thorough investigation surrounding the cause of death,” stated Jennifer Rainey, Public Information Officer. “However, current knowledge of medical and travel history do not indicate an ongoing public health threat to Denton County residents.”

The man was taken to the Tarrant County Medical Examiner’s office for an autopsy.

As the investigation proceeded, it was determined that there were no signs of any infectious disease or traumatic injury and it is believed that an underlying medical issue led to the man’s death.