According to SurvivalLife.com, Hawaii, Maine, New Mexico, and Wisconsin have explicit laws that make butterfly knives unlawful. Numerous additional states have various restrictions on these knives.
Some states consider a butterfly knife, also known as a Balisong knife, to be dangerous and unlawful due to its ease of use as a lethal weapon. In certain places, such as Tennessee and Washington, the legality of these knives hinges on whether or not they are considered switchblades. These knives are permitted in Wyoming, North Dakota, and Oklahoma so long as they are not concealed. In New Hampshire, convicts convicted of crimes against people or property are prohibited from possessing them, and in New York, noncitizens are prohibited from carrying them. New York may additionally require owners of these knives to have valid hunting or fishing licences in order to carry them.
The owner of a butterfly or Balisong knife must be informed of their state’s laws as well as the laws of other states they may visit. Even possessing one of these knives in a vehicle while crossing state boundaries might result in prosecution.