Colorado police charged a man with reckless endangerment and discharging a weapon after he opened fire to try to apprehend a fleeing robbery suspect in Aurora.

A bystander, identified as Avery Nelson, sprang into action after a masked man allegedly robbed a Subway restaurant and physically assaulted a female employee around 7:40 p.m. on Saturday. As the robber escaped with the cash, the man stepped in and chased him down to try to make a citizen's arrest.

"I saw two females screaming and ducking for cover," he told CBS Denver.

That's when Nelson began running after the suspect through a strip mall and sprayed him with mace. The suspect, however, kept running. Nelson then pulled out his gun and fired two warning shots in the air. He also shot at the suspect's car, but the perpetrator still managed to get away.

Nelson was later issued a summons.

"When you fire rounds into the air you have no clue where those rounds may end up and if they'll strike anybody," Aurora Police Sgt. Chris Amsler told KUSA. "Chasing this guy, firing rounds into the air, shooting at the vehicle, put the public at risk and endangered them."

"In this situation we would prefer anyone, whether they're a bounty hunter or not, to be a good witness. To get a good description of the suspect, of the vehicle, and then give it to the police when they get there," Amsler added.

However, Nelson, who happened to be a trained fugitive recovery agent, argued that he thought the suspect was a threat to the community.

"I did feel that my life and the lives of the people in my community were in danger. So I wanted to stop that person," he said. "He was turning, slowing down, as if he were to attempt to draw a gun, so I wanted to deter that threat."

As of Sunday, the suspect was still on the loose. Meanwhile, the Subway worker suffered minor injuries from being punched, slammed to the floor and kicked in the ribs.