Todays quick opening knives still require the use of partial release by the thumb knob on the blade. If in doubt, ask a District Attorney for a legal opinion by mail so that you have proof in writing in case some local peace officer thinks it should be otherwise.

Back in the old days when switchblade and gravity knives knives were made illegal, they used to make an Italian stiletto with a fingernail groove that was required to lift the blade slightly from its closed position whereupon you could swing the blade into the open and pin locked position. The problem with those was that in order for it to work well, you needed to have a 5" or larger bladed knife for sufficient mass and to create the required inertia. The size of the blade then made it illegal no matter how it was opened.

In some states in the USA, possesion of a bayonet or dagger style blade in and of itself is illegal no matter how small the knife.

Bountyhunter