Thousands of construction and other workers say they have been wrongfully arrested and prosecuted for carrying utility knives. Their arrests have touched off a legal battle in Albany. NY1 Criminal Justice Reporter Dean Meminger speaks exclusively with an NYPD expert about the controversial blades.

The NYPD says state legislators are playing with danger trying to relax a decades-old law governing gravity knives.

That’s a knife where the blade is in the handle, but opens quickly by the force of gravity.

"Gravity knives or certain knives that can be deployed rapidly under certain circumstances can pose a risk to police and civilians," said NYPD Detective Patrick DeCanio with the Firearms and Tactics section.

Problem is many workers carry utility knives that can quickly open with a flick of the wrist.

The Legal Aid Society says those knives aren't the traditional gravity knives that are outlawed.

But over the last 15 years, the civil rights organization claims, the NYPD has been treating utility knives that way, wrongly arresting tens of thousands of people for carrying them. 

Electrical worker Jason Ferguson says his utility knife was clipped on his pocket when he was arrested. 

"I had my Dewalt power tools in my left hand and these cops approached me for no reason and it is very clear I am coming from work," Ferguson said.

He sued, and reached a settlement with the city.

"I was locked up for two days," Ferguson said. "I feel like a criminal and I am not. I am an electrician."

Joshua Fitch represents workers in a class action lawsuit who say the NYPD falsely arrested them for what they consider legal knives. Fitch says trained cops are snapping the knives open and then charging people with having gravity knives. 

"And their interpretation is that any knife that anyone can open by flicking their wrist is a gravity knife which is simply not the law," Fitch said.

I practiced trying to open three different knives, one was pretty easy, the other two pretty hard to do, but after some practice and adjusting my technique, I was able to open it almost every time.

Governor Cuomo is reviewing a bill passed by the legislature to legalize folding utility knives that tend to stay closed unless forced open. 

Gravity knives would remain illegal.  

The NYPD opposes the bill, saying it could increase the amount of people carrying knives.