Wiktionary
n. A police nightstick used originally in Baltimore, Maryland. An espantoon differs from a nightstick in its attached leather hand strap from the espantoon can be swung.
Wikipedia
The espantoon is a wooden truncheon, equipped with a long leather strap for twirling. It originated, and is still strongly associated, with the Baltimore Police Department in the city of Baltimore, Maryland. The term is considered distinctly Baltimorean.
The word itself derives from that of a pole weapon, the spontoon, which was carried by infantry officers of the British Army during the Revolutionary period. Since, the espantoon has been considered a symbol of the "policeman's office and dignity". Before the advent of wireless communications, the espantoon was reportedly used by Baltimore policemen to call for assistance where its user would bang it on the curb or a drainpipe.
In 1994, Thomas C. Frazier took over as Baltimore's police commissioner and banned the espantoon. Frazier, a Californian, believed that the device, and the policemen's twirling of it, was intimidating to the civilian populace. He attempted to replace it with another weapon, the koga baton, much longer at 29 inches without a strap or handle. Many officers, however, felt that the koga was cumbersome, difficult to master, and even more dangerous than the espantoon.
In 2000, Edward T. Norris assumed the office of police commissioner and lifted the ban on the espantoon, although he did not mandate its use. The move was made as part of a general effort to boost morale and instill a more aggressive approach to policing in Baltimore. Norris stated, "When I found out what they meant to the rank and file, I said, 'Bring them back.' ... It is a tremendous part of the history of this Police Department."