By Peter Honigmann


The streets are dangerous, no matter where you live or where you travel. One item you may consider carrying for self-defense, or perhaps you are already carrying, is a knife. Either way, being familiar with the law is important, because if you end up using that knife to defend yourself, you may now have to face serious legal ramifications, which could include jail time.

Have you heard the phrase, “ignorance of the law is not a defense”? Well, in the United States you are assumed to know the law. Actually you are presumed to know all of the laws, which we all realize is not only unrealistic, but impossible. And while it’s not possible to know every law on the books, it is certainly in your best interests to be familiar with those laws that are most likely to apply to you, especially when you’re carrying something like a knife, which can cause serious injury or death to another person.

A good place to start your research is the internet. Are you a person who travels across state lines?  If so, you will need to look at the laws in the states where you tend to spend the most time, or perhaps a state where you plan on moving, or will be spending a significant amount of time. There are several websites out there that have collected information on knife laws for all 50 states; start there and follow up on the references they provide so you can go right to the actual source.

What you do not want to do is read a website or the comments provided on a blog about knives, and take those statements as fact, since those comments are really only other people’s opinions interpretations of the law. There are really only two ways to truly understand any statute or ordinance, the first is to read it for yourself, and then read any cases where the courts have interpreted that law (since the plain reading of the law may not be as clear as you might think), or find a competent lawyer and ask the lawyer to explain it to you.

Let’s assume you live in Illinois (like me), and you want to know the law about carrying a knife. Where would you start?  Well, in Illinois the state laws are referred to as the Illinois Compiled Statutes and can be found free online, or found in bound volumes at any law school library (which is generally open to the public).

The Illinois’ law regarding knives can be found at 720 ILCS 5/24-1, and that section is entitled “Unlawful use of weapons,” so clearly it refers to more than just knives. Without reciting the entire law here (you should go and read it for yourself), it states in part:

“a person commits the offense of unlawful use of weapons when he knowingly:

(1.) Sells, manufactures, purchases, possesses or carries any bludgeon, black-jack, slung-shot, sand-club, sand-bag, metal knuckles or other knuckle weapon regardless of its composition, throwing star, or any knife, commonly referred to as a switchblade knife, which has a blade that opens automatically by hand pressure applied to a button, spring or other device in the handle of the knife, or a ballistic knife, which is a device that propels a knifelike blade as a projectile by means of a coil spring, elastic material or compressed gas.

(2.) Carries or possess with intent to use the same unlawfully against another, a dagger, dirk, billy, dangerous knife, razor, stiletto, broken bottle or other piece of glass, stun gun or taser or any other dangerous or deadly weapon or instrument of like character.”

This law is rather poorly written, as many laws are, so reading through it you may notice that it makes reference in the second paragraph to a “dangerous knife”, which does not appear to be defined here. If you do some searching you will find that language is actually located in a different section, 720 ILCS 5/33A-1, which is entitled “Legislative intent and definitions,” which states:

(c)  Definitions.

(1) “Armed with a dangerous weapon”. A person is considered armed with a dangerous weapon for purposes of this Article, when he or she carries on or about his or her person or is otherwise armed with a Category I, Category II, or Category III weapon.

(2) A Category I weapon is a handgun, sawed-off shotgun, sawed-off rifle, any other firearm small enough to be concealed upon the person, semiautomatic firearm, or machine gun. A Category II weapon is any other rifle, shotgun, spring gun, other firearm, stun gun or taser as defined in paragraph (a) of Section 24-1 of this Code, knife with a blade of at least 3 inches in length, dagger, dirk, switchblade knife, stiletto, axe, hatchet, or other deadly or dangerous weapon or instrument of like character.

After reading this you might get the impression that it is illegal to carry a switch blade or a knife with a blade that is over 3 inches; however, that’s not quite accurate. First, you can carry a knife with a blade length over 3 inches, so long as you do not have the “intent to use the same unlawfully against another.” So as long as you carry the knife for a lawful purpose, it is legal. As for the switch blade, once again this section of the statute alone does not provide the entire story. The exception to this section can be found at 720 ILCS 5/24-1 section (e), which is entitled “Exemptions,” which says,

(2) The provision of paragraph (1) of subsection (a) of this Section prohibiting the sale, manufacture, purchase, possession, or carrying of any knife, commonly referred to as a switchblade knife, which has a blade that opens automatically by hand pressure applied to a button, spring or other device in the handle of the knife, does not apply to a person who possesses a currently valid Firearm Owner’s Identification Card previously issued in his or her name by the Department of State Police or to a person or an entity engaged in the business of selling or manufacturing switchblade knives.

Now that you’ve read the exception to the rule, you’ve learned that in fact you can legally carry a switchblade knife, but only so long as you possess an Illinois State Firearm Owner’s Identification Card (“FOID”).

You’ve now done your due diligence, and determined that you can legally carry a knife in Illinois with essentially any length blade, including a switchblade, so long as you do not intend to use it illegally. At this point you might believe you are street legal, but hold on, not so fast. Illinois allows cities to regulate the carrying of weapons as well, so you need to also have some understanding of the local ordinances in the cities and towns where you spend a lot of time, say Chicago. In order to learn about the law in Chicago, you need to take a look at the Chicago Municipal Code, and there you will find this section which states:

  • 8-24-020 Sale or possession of deadly weapons

(f.) No person shall carry concealed on or about his person a dagger, any knife with a blade more than two and one-half inches in length, or other dangerous weapon. 

Essentially in the state of Illinois I am legally allowed to carry a knife with a blade length of 3 inches or more, or even a switchblade, so long as I have a FOID card, unless I am within the city limits of Chicago, and then I can’t carry either of those. It seems unbelievable to me that I can be completely legal in most of the state, but then by crossing an invisible boundary within my own state, I am now considered a criminal. Unfortunately, that is the state of Illinois, which allows the cities the right to pass more stringent laws than those enacted by the state government, which creates a real nightmare for those of us who are doing our best to protect ourselves while trying to be law abiding citizens.

Stay safe by knowing your rights and understanding the law so you do not end up looking from inside a jail cell.