The alleged attempted robberies took place on Monday at two downtown Washington banks, The Washington Post reported.
At the the SunTrust bank, the suspect, whose name was not reported, walked in and gave a teller a note that read "100s 50s 20s 10s."
"The teller was confused," an FBI agent wrote in an affidavit filed in federal court, noting that the teller said the suspect said "money," but nothing else. She handed the note back, and the FBI said the suspect wrote, "all mona."
However, the teller sent him away. A nearby customer informed the teller that the man was trying to rob the bank.
Shortly thereafter, the suspect entered the Bank of America and handed a teller there the same note.
The teller there quickly understood what was going on and asked "Oh my God, are we getting robbed?" the affidavit stated.
She alerted security guards at the bank and the man took off. Police caught up with him about three blocks away and charged him with two counts of attempted bank robbery, authorities said.