PHILADELPHIA (WPVI) -- One suspect is in police custody and others are being sought in a series of armed robberies that are terrorizing convenience store employees and customers in Philadelphia and surrounding areas.Police tell us a violent gang of bandits may be responsible for upwards of two dozen crimes, including the shooting of a Philadelphia cab driver.Police released surveillance video they say is from the brazen crew's first commercial robbery. Two men enter Pete's Pizza on the 4400 block of Lancaster. Employees scatter. The suspects then force an employee to the front of the store, steal cash and flee."It was towards the end of the night around 12, a guy came in with a hood, he had the hood strapped real tight to his face," said Richard Carol, Pete's Pizza.A month later, police say the crew struck again. This time Richard Carol was at the front counter getting ready to close up."Once I noticed what was going on, I told everyone to run to the back. Everybody shot to the back, and I turned the lights off," said Carol.They ran out the back door and were uninjured.Investigators say as many as a dozen teens and young men are part of the crew that's been terrorizing businesses from Tinicum to Philadelphia to The Main Line."Basically they are heavily-masked. They enter businesses, all diff types of businesses. Mostly minimarts, pizza stores, Wawas, 7-Elevens," said Philadelphia Police Lt. John Walker.Southwest Detectives Lt. John Walker says one man, identified as Marquise Carter, made a mistake and left his phone at a crime scene. Detectives arrested him last week. He's charged in three of the crimes, but police believe the 22-year-old is the ring leader."They've also stolen two cars from two local dealerships, one in Lower Merion and one in Philadelphia County, that we believe they've been using in these robberies," said Lt. Walker.Lt. Walker believes the gang is also responsible for the robbery and shooting that left a cab driver in critical condition on Jan. 15. Now police want help catching the at large criminals who continue to strike."They haven't stopped, even thought we have Mr. Carter in custody. We had an incident on the 23rd, so we know they are out there," said Lt. Walker.