Story highlights NFL linebacker Dan Connor was released after his arrest

Screeners found a 4-inch switchblade in his luggage, police say

The Giants say they are "cooperating with authorities"

New York Giants linebacker Dan Connor was arrested after baggage screeners at Philadelphia's airport found a four-inch knife in his carry-on luggage, police said.

Connor was charged with posession of an offensive weapon after the switchblade showed up in an X-ray Saturday morning, Philadelphia Police spokeswoman Christine O'Brien told CNN. Transportation Security Administration screeners called in Philadelphia police, and Connor was taken into custody, O'Brien said.

He was released on his own recognizance after being processed and arraigned, she said.

The Giants signed Connor as a free agent in the spring after he spent a year with the Dallas Cowboys. The Charlotte, North Carolina, resident played four seasons for the Carolina Panthers before joining the Cowboys.

"We're aware of the situation and we spoke to Dan yesterday and we are cooperating with authorities," Giants spokesman Peter John Baptiste said in a written statement.

Federal authorities banned knives aboard aircraft after the September 11, 2001 al Qaeda attacks on New York and Washington. A proposal by TSA chief John Pistole to loosen that ban to allow knives smaller than 2.36 inches failed in June after fierce criticism from airlines, unions and Congress.