The Phoenix Police Department says a witness shot and killed a man who was trying to rob a Walgreens.

According to Phoenix police, the suspect approached the Walgreens pharmacy counter and demanded oxycodone. The suspect was wearing a wig at the time. 

The armed customer who shot the suspect is cooperating with police as they continue to investigate. No other injuries are reported.

The incident happened Tuesday around 7:10 p.m. local time at the store near 35th Avenue and Union Hills.

Life saving efforts were performed on the suspect who died from his injuries at the scene. 

There were about a dozen people inside the store at the time of the robbery and shooting. 

Deadly force can be used to defend yourself or others in the state of Arizona; police are investigating the incident, it's unclear if the armed customer will face any charges.