Last Updated on June 17, 2026 by Michelle Ball

Many students are suspended or placed up for school expulsion for possession or brandishing knives. What a “knife” is, is obvious, right? Not so much. What legally counts as a “knife” for school expulsion is strictly defined by the California Education Code.

So, did the student actually bring a knife, or not? The answer may surprise you. (and P.S. not all schools even know!)

The Legal Definition of a Knife in School Expulsions

Per Education Code section 48915(g) a weapon which is a “knife” for purposes of a student school expulsion is:

[A]ny dirk, dagger, or other weapon with a fixed, sharpened blade fitted primarily for stabbing, a weapon with a blade longer than 3 1/2 inches, a folding knife with a blade that locks into place, or a razor with an unguarded blade.

Okay- you may feel like you are somewhere back in time when trying to figure out what a “dirk” or “dagger” is, but these are not the most common items students possess in schools.

The Two Most Common Knives Students Have at School

In schools, more students tend to bring certain types of “knives.” The two definitions of “knife” which apply most often, are:

1)  Weapon with a blade longer than 3 1/2 inches

2)  Folding knife with a blade that locks into place.

These encompass things like Swiss Army Knives, folding multitools with blades that lock, steak knives or kitchen knives. The locking nature of that boy scout knife, or the fixed nature of a steak knife little Johnny picked up, matters.

Parents, make sure your kids don’t bring their fishing gear or boy scout tools with them to school on Monday, of they could be sorry later.

Why Students Unintentionally Get Caught With Knives At Schools

The reason students sometimes end up nailed with possession of a “knife” at school is this: a student goes fishing over the weekend, leaves his multitool, key chain, or Swiss Army Knife with a blade that locks into place in his pants pocket, and throws those same pants on Monday. He then has a “knife” at school.  

It does not matter if the student did not intend to bring the knife to school, nor that he used it for fishing and forgot about it.

A student will likely be in big trouble if it is discovered at school, or used.

Of course, many students, finding a multitool or knife in their pants pocket while at school, take it out, fiddle with it in class, show it to friends, or simply use it to do something unimportant.  That is a very very bad idea.  

Locking Blades, Regardless of Size Fit the Knife Definition

Even if a “knife” blade is minuscule, dull, and looks like it could not hurt a bug, if it locks, the school may choose to apply their “zero tolerance” viewpoint and put a student up for school expulsion. This is because a locking blade, regardless of size, is a “knife.”

What if the Blade Does Not Lock?

If the same multitool does NOT have a locking blade, the length of the blade will have to be measured. Per the law, the issue is whether the non-locking blade is 3.5 inches or larger.  

If a blade is 3 inches long, attached to a multi-tool, and not “primarily for stabbing,” this may open a door for a really good defense on a knife allegation, as the object may not be a “knife” per the legal definition.  

Please note: the student still may be put up for school expulsion for other reasons such as possession of a weapon or “dangerous object,” but that is a story for another day.

School Personnel May Not Understand “Knife” Nuances

Now, don’t count on the schools understanding the nuances of weapons or the legal definition of a “knife” in expulsions. They also don’t often listen to parents’ interpretations of the law.

So, this may be best argued by the student’s legal counsel. Regardless, parents can show school officials the legal codes and challenge them.  

Check the Law First

If a student is up for expulsion for possession of a knife, check the legal definition of a “knife” related to school expulsions to be sure what they have really IS a “knife.”  If it isn’t, then any discipline for student possession of a “knife” may be open to attack.

Student suspension and expulsion lawyer Michelle Ball helps with school expulsions for knives, fights, weapons, and many other expulsion bases. As an attorney in Sacramento Michelle can reach across California, to places such as Los Angeles, San Francisco, Santa Rosa, Roseville, Auburn, Tahoe, Elk Grove, Natomas, Carmichael, Vacaville, and tons of other California locations.

Originally published September 14, 2011