Here is the long and short of weapons in NJ. Whether something is considered a weapon (not including firearms, that is a whole other subject) in NJ is based on intent, and the interpreted intent of the police officer. Here is a short break down:

If you have a baseball bat in your car and get stopped by a police officer he can view it as a piece of sporting gear or a weapon, and here are two scenarios:

[A]: You get stopped with a bat in your vehicle and are wearing a baseball uniform, athletic attire, etc. It would be hard for said officer to prove your intent was anything other than that of using it as sporting equipment.

[B]: You are in a high crime area, in "street" attire, with a bat in your car. The officer could/would/may interpret this as you having a weapon based on intent. Intent meaning you are in a bad neighborhood, dressed like a criminal, with an implement that can be used for commission of a crime.

Same would apply for a knife, hammer, 2x4, etc. If you are wearing a kilt, and have a sgain, an officer would have a heck of a time showing probable cause to suspect criminal intent. You need to remember in NJ, and most states, police officers have what is termed legal discretion. The same way a cop can pull you over for speeding and decide whether he is going to give you a ticket, or let you off with a warning.

Most cops are cool folks, and would actually be more interested in having you explain your attire and accessories, than harass you. As long as you are not obnoxious or rude and give them due respect, I doubt there is need to worry.

I never got people's fear of police. They view there job just like any other line of work, it's a job and it pays their mortgage.