Butterfly Knives


How many legs does a dog have, if you call a tail a leg?

On two criminal-defense lawyers’ email discussion lists, the topic of balisong or butterfly knives came up recently. The consensus on both occasions was that such knives are outlawed by section 46.05 of the Texas Penal Code, which makes it an offense to possess a “switchblade knife.”

“Switchblade knife” is defined by section 46.01 of the Texas Penal Code as “any knife that has a blade that folds, closes, or retracts into the handle or sheath, and that: (A) opens automatically by pressure applied to a button or other device located on the handle; or (B) opens or releases a blade from the handle or sheath by the force of gravity or by the application of centrifugal force.”

The consensus among criminal-defense lawyers was that a butterfly knife opens by the application of centrifugal force. There are two Texas centrifugal-force knife cases, both from Houston’s First Court of Appeals and both “unpublished” opinions. The older of the two, Smith v. State, No. 01-87-830-CR, concerned a butterfly knife; according to the court, “Ample testimony of the knife’s functioning revealed that the knife could open by centrifugal force after being unlocked.” There was no mention of any testimony to the contrary.

I am looking for one of these cases to try.

Here is a New York case saying that a butterfly knife doesn’t have “a blade that is released by the application of centrifugal force.” Here is an Oregon knife expert who will so testify. But neither of these resources addresses what I think is the definitive defense in a Texas butterfly knife case:

There’s no such thing as centrifugal force.

It wouldn’t be hard, and could be very entertaining, to parade any number of experts from the local university through the courtroom to explain that centrifugal force is an illusion.

This invites us to ask: does the legislature’s inclusion of it in the statute constitute a legislative finding that it does exist? No. If you call a tail a leg, a dog still has only four legs.


0 responses to “Butterfly Knives”

  1. Thanks for the comment, Quash.

    If the State were to offer expert testimony in line with the link you sent, I would welcome it. Why? Because I think think I win anyway, and I would like for our courts to start looking at things from other frames of reference than their own. See here.

  2. Good stuff. I think it is critical to give jurors the idea/option of looking at the facts from new perspectives, including any they come up with on their own. I am absolutely certain that I have had clients acquitted because some juror was sharper than I am and became the advocate my client needed.

  3. I have testified as an expert in a few cases like this in Oregon, and in addition to the fact that a centrifugal force is fictitious (or only felt in the rotating frame), we have addressed two other issues. These are (1) the fact that even if the statute makes physical sense, members of the public have no idea what it means, and (2) even if the statute makes sense and the public knows what it means, the centrifugal force is NOT what makes the knife blade move into position. It’s the blade’s own inertia that does that.

    Shawn Kolitch
    J.D., Ph.D
    [email protected]

Leave a Reply

Your email address will not be published.