When do bank heists happen?
Bank robberies aren't a common occurrence.
Johnson says there are nearly 100,000 U.S. bank branches, and only about 6,000 to 7,000 robberies per year.
The FBI counted 5,014 bank robberies of federally insured deposit institutions in 2011, the most recent year for which data has been released. Robberies occurred during all normal business hours, though they were somewhat more likely to occur on Fridays or between 9 a.m. and 11 a.m. any weekday, according to the FBI statistics.
A total of 201 robberies involved the discharge of firearms, explosives or physical assault. In those robberies, 88 people were injured, 13 died and 30 were taken hostage. Most of those hurt or held were bank employees. All of those killed were perpetrators, law enforcement officers or, in one case, a security guard.