The police report of the incident said the officer was on patrol Saturday when he stopped at a PDQ convenience store for refreshments.
The officer noticed another customer acting suspicious in the store and witnessed the customer display a weapon and demand money from the clerk, the report said.
The report said the officer identified himself and ordered the suspect to stop. The man dropped his weapon and fled on foot, leading the officer on a chase for several minutes until he was apprehended.
The police report did not identify the 34-year-old suspect by name. It did not say whether the police officer was in uniform at the time of the incident.