Scary Moment When Would-Be Robber Pulls a Gun on Taxi Driver

— -- A taxi driver found himself in a dangerous situation after picking up a man earlier this week.

A deputy sheriff who was in the car behind the taxi inadvertently thwarted an armed robbery in progress after noticing that the taxi wasn't moving at a traffic light, according to police in Reading, Pennsylvania.

Reading Police Capt. Damond Kloc told ABC News that the incident occurred Monday afternoon when driver Ralph Valletta was threatened with what appeared to be a gun by the man.

Video footage from inside the car recorded the suspect, later identified as 18-year-old Victor Martinez-Herrera.

"Give me all your money man! Give me everything you got!" Martinez-Herrera, who had pulled his hood tight around his face and used what appears to be a scarf to hide the rest of his face, is heard saying on the video.

Kloc said that the incident occurred on Valletta's first pickup, so he only handed over less than $20 and a cellphone.

The incident happened at an intersection's red light, and when the taxi didn't move after the light changed, the sheriff's deputy in the car behind the taxi approached the car to investigate, Kloc said.

"The traffic signal had gone through a couple cycles and so he wanted to go up and investigate what the issue was," Kloc said of Berks County Deputy Sheriff Terry Ely.

Ely then detained the suspect at gunpoint and called for assistance.

ABC affiliate WPVI reported that the driver can be heard telling Ely "You're a lifesaver!"

Martinez-Herrera has since been charged with robbery, making terroristic threats, simple assault and harassment. Since the weapon he used was a pellet gun, he was also charged with possession of a prohibited offensive weapon.

Martinez-Herrera, who was arraigned Monday, has not yet entered a plea and is still in police custody. WPVI reported Martinez-Herrera's bail was set at $100,000.