Slap jacks are also known as police leather slaps or blackjacks. While blackjack is a widely used name there is also a fine distinction since blackjacks can also refer to a similar instrument that is made with a round piece of lead as opposed to the flat profile of this device. The other name for it, although not always in use in is beavertail sap. This is actually a more accurate descriptive name since it does have the shape of a flat beaver tail.
The history or lineage of this equipment seems to belong to those of the baton or truncheon. Current literature lumps this weapon in the same group as the baton, truncheon and billy club. It would seem to be another variation of these types of weapon.
The device gain some sort of notoriety in the 1940’s since it was then associated as a weapon of choice for those on the other side of the law. This was also a popular equipment of cops of the older generation or the so called “old school” cops. Other devices such as the expandable baton have replaced this equipment in majority of the police service units.
There is some argument as to why it was replaced, with some stating that it had more to do with improving police image since it could be used to “slap” or wack a rowdy offender into place and can cause some serious damage when struck in the head. Hence it could be a reason for complaints on police abuse.
A slap jack can be made of different materials but the higher end ones are made of leather. It is a flat poach and like the shape of a beaver tail with the bigger flat side being the clubbing end containing hard material the most favored one being lead. Higher end models have a spring along the entire length of the instrument.
The device is quite convenient since the smaller models are 8 inches in length can be easily placed in a pocket and therefore not that easy to grab by an assailant. Its small size is also like a surprise package since the opposing side may not even know it’s there.
It can pack quite a punch without exerting excessive effort. For law enforcement agents who can still carry this equipment, they are advised to hit at non-critical locations like large muscle areas. A broken bone or skull fracture is possible with this device.
It is very useful in close quarter situations and as a defensive device is used as a weapon that can provide distance between you and the assailant. After striking the assailant it is advised to then run and gain distance away from the attacker. Some have even used this device to ward off dogs.
While it may have lost favor with most police departments in the U.S., it may had more to do with maintaining good public image. Certainly it has not lost is effectiveness as a self defence instrument.
As with any product of this nature, please check to see if this is legal in your community.