See tweet from NYPD Commissioner Sewell here 

“The alertness of two NYPD transit bureau officers at a Brooklyn station prevented a gun from getting into the subways and we are grateful for their diligence and commitment to protecting riders. When a person they stopped for not paying the fare turned out to have an outstanding arrest warrant and a search was conducted, a loaded gun was recovered from the man’s pocket -- a gun that otherwise would have been brought into the transit system. As we have said repeatedly, when bad actors know they can be stopped at the entry gate, they are less likely to take a chance on coming into transit to commit crimes against other New Yorkers.”