The case is State v. Montalvo and where defendant Crisoforo Montalvo was convicted of unlawful possession of a weapon for greeting an aggressive and threatening neighbor at the door with a machete in his hand. The New Jersey Supreme Court remanded the case for retrial, but there is a larger significance to the ruling.
Eugene Volokh describes this significance in his piece for the Washington Post.
The New Jersey machete decision is important because it rejects a “spontaneity” requirement for arming yourself at home (the state’s theory that you could pick up a weapon against an imminent attack, but you can’t come to the door with the weapon just in case). But it’s also important because it reaffirms that the Second Amendment protects not just guns but other weapons as well.
This should be obvious, I think: The Second Amendment protects “arms,” and the D.C. v. Heller opinion discusses bows and knives as examples of such arms; opinions in the 1800s and 1900s dealing with state constitutional rights to bear arms also mention bladed weapons; and post-Heller opinions, such as from courts in Connecticut, Michigan, and Wisconsin agree.
Volokh has a separate piece which excerpts significant pieces of the decision. One jumps out at me in particular.
Individuals may possess in their homes objects that serve multiple lawful purposes, including the purpose of anticipatory self-defense. In this case, Montalvo possessed at home a machete he used in his roofing job. He was lawfully entitled to possess that machete as a weapon in his home as a means of defending himself and his family from attack as well. The right to possess that weapon, however, does not mean that it can be used without justification.
An individual who responds to the door of his home with a concealed weapon that threatens no one acts within the bounds of the law. He need give no justification for what he is lawfully allowed to do.
This unanimous! decision from the notoriously hoplophobic state of New Jersey is quite surprising. Even a blind squirrel finds a nut as they say.