Ed Mullins, head of the New York Police Department Sergeants Benevolent Association, doesn’t want to look back at a terrorist attack in an NFL stadium -- like the one at the Stade de France Friday -- and wonder what could have been done differently to stop it. One thing that could stop a possible attack? Allowing off-duty police officers to have their guns in the stadium, something the league banned in 2013, according to Mullins.

“The real question is, do we want to be sitting back … questioning the policies of the NFL, asking why they instituted these policies if something happened?” Mullins said.

Citing the Paris terror attacks that left 129 dead and hundreds injured, the Sergeants Benevolent Association launched a petition to get the NFL to allow off-duty police officers to carry firearms in its stadiums. Proponents argue that it is an officer’s duty to jump into a dangerous situation, whether he is on the clock or not. But while having the free extra help could be beneficial in a moment of terror, allowing off-duty officers to use their guns during a terrorist attack could also create more chaos, some experts said.

The Paris attacks included a series of suicide bombings at the Stade de France where a soccer match was being played. Amid heightened tensions, a German soccer stadium was evacuated Tuesday before a game, just days after the Paris attacks.

In a statement Saturday, the NFL said the Department of Homeland Security has certified its security procedures. The league said it was closely monitoring events after the Paris attacks and that it would have extra security at games.

The NFL said in 2013 that off-duty cops carrying guns should no longer be admitted into its stadiums; the policy was reached after consulting with law enforcement personnel. “We concluded that public safety inside NFL stadiums on game days would be best-served by the carrying of firearms by on-duty officers specifically assigned to work the game as part of the comprehensive public safety plan for the event,” Brian McCarthy, an NFL spokesperson, said in an email.

The Sergeants Benevolent Association started the petition on Change.org Monday calling for NFL Commissioner Roger Goodell to reverse current league policy, saying it is a public safety issue. The petition had a little more than 1,800 signatures by Wednesday afternoon.

Police respond to dangerous situations every day -- uniformed or not, said Dennis Flaherty, executive director of the Minnesota Police and Peace Officers Association, the largest association representing police in the state. Having no weapon takes away an important tool in an officer’s tool chest, and decreases the likelihood that an officer could help in a dangerous situation.

“It happens in every town and city in America,” Flaherty said. “[Police] disregard whether they’re on or off duty and they respond, and quite frankly they're expected to do that; it’s the way of life for a police officer.”

If the off-duty police at a game register their guns with security, making it known that they are ready to step into a situation at a moment’s notice, having armed off-duty police may increase security, Lou Marciani, director of the National Center for Spectator Sports Safety and Security at the University of Southern Mississippi in Hattiesburg, said.

“If I know that you registered with me and I know you’re in section six, row six, and I need help I can go to you,” Marciani said. ”It would be a logical way of bringing [an off-duty officer] into the system.”

But having a gun may not be such a simple solution to a terrorist attack, even if police are trained in firearm use.

“A trained person with a gun in a moment of crisis might theoretically be a good idea, but what we also know is that more arms in stadiums can pose a security threat,” Juliette Kayyem, a lecturer on national security at the John F. Kennedy School for Government at Harvard University in Cambridge, Massachussets, said. 

Most stadiums already have security personnel with guns, and having additional off-duty police trying to respond to a dangerous event might escalate the situation by misreading it, Kayyem, a former assistant secretary for intergovernmental affairs in the Department of Homeland Security, said. On-duty security personnel have very specific plans of what to do in a dangerous situation.

While an off-duty officer may have the best intentions, that officer likely wasn’t involved in how the on-duty security team are trained, Marciani said. Security staff members aren’t just hired — they’re trained on and often practice how to respond to dangers.

McCarthy also said that security officers at games are trained with specific safety protocols in mind, and have an established chain of command. Off-duty police are considered spectators at games, aren’t known to the on-duty security and may have separate training from the on-duty officers, he said.

Other concerns could include off-duty officers consuming alcohol while armed, and on-duty police possibly mistaking an off-duty police officer responding to a dangerous situation with a gun as someone who shouldn’t have a gun, Darrel Stephens, executive director of the Major Cities Chiefs Association, a group of sheriffs and police chiefs from large cities in the U.S., U.K. and Canada, said.

“There could be some concern about being able to identify yourself as an off-duty officer in those circumstances,” Stephens said. “Not being easily identifiable presents a bit of a problem.”

Flaherty, however, said when police take action, they can’t be mistaken for anything but an officer of the law. “Believe me if they spring into action they will make their presence known that they are a police officer, and again it’s done every day,” Flaherty said.