FBI Special Agent Sean Quinn told The Newark Star-Ledger that the FBI early Monday arrested a man "who fits the general description of the Mad Hatter."
The suspect's name was not immediately released. Quinn said investigators were trying to confirm his identity.
Authorities believe the robber known as the "Mad Hatter" held up 17 banks in northern New Jersey between last year and Sunday, when he robbed a Bank of America branch located inside a supermarket in Union around 11:30 a.m. He walked out with $5,000.
"I couldn't believe it. I still can't believe it could happen to this store," shopper Victor Astone told WCBS-TV.
"We're surprised, very surprised because things like this don't happen in Union," Rae Astone said. "But it happened today."
Despite the nickname, the "Mad Hatter" never made a big scene. He just walked into banks, handed tellers a note demanding money, got it and walked off.
Altogther, reports the Star Ledger, he's acquired more than $60,000 from the robberies. He's believed to be a white male in his 40s or 50s.
Police said he was nondescript — a middle-aged white man of average height and build who sometimes wore a flannel shirt, sometimes a blazer.
But every time he donned something on his head. He wore various baseball caps, a fishing hat and a hunting hap. Hence the nickname, which comes from a character in the children's classic "Alice in Wonderland" who wore a top hat.
Authorities said the publicity surrounding the case may have touched off some copycat robberies.