A 72-year-old man died last month after another man punched him outside a truck stop, the Aurora Police Department announced Thursday.

Police said the incident happened May 17 just before 6 p.m. in the parking lot of the Flying J truck stop at 16751 E. 32nd Ave.

According to the investigation, the victim got into an argument with the man in the parking lot, which led to a physical fight. During the fight, the man punched the victim, causing him to fall backwards and hit his head on the ground.

The victim, identified as Kevin Stymiest, was taken to a hospital and pronounced dead three days later.

The man who punched the victim has been identified and is cooperating with the investigation, police said, but did not release his name.

The police department’s Major Crimes Homicide Unit is working with the District Attorney’s Office to determine if criminal charges should be filed, police said. The case was initially being investigated as an accidental death until autopsy results from the Adams County Corner determined it was a homicide, police said. The homicide investigation is continuing.

Anyone with information is asked to call Metro Denver Crime Stoppers at 720-913-7867. Tipsters can be anonymous and are eligible for a $2,000 reward.