The 17-year-old, whose name was not released because of his age, was arrested at John Dickinson School on Wednesday where he is a student.
The other suspect, 21-year-old Nikkia Earl of Wilmington, turned himself in on Wednesday.
Police say the pair cooperated in the robbery of the TD Bank branch on Route 202 in Concord Township, Pa. at 10:30 a.m. on October 8th.
The teen is charged with robbing two banks on his own: The TD Bank branch at 1803 Marsh Road in Wilmington around 11:50 a.m. on October 8th and the Wachovia Bank branch on Marsh Road in Wilmington at 4:40 p.m on October 14th.
Earl, meanwhile, was charged with robbing the WSFS Bank Foulk Road in Wilmington at around 11:25 a.m. on October 8th.
Detectives were able to develop the 17-year-old and Earl as suspects from evidence that was recovered from the bank robbery that had occurred in Pennsylvania.
Detectives then executed search warrants at the home of the juvenile as well as Earl's residence where further evidence was recovered.
The teen was arraigned at JP Court 2 and committed to the New Castle County Detention Center for lack of $200,000.00 bail.
Earl was also arraigned at JP Court 2 then committed to the Howard Young Correctional Facility for lack of $25,000.00 cash bail.