The two armed men arrested this weekend for allegedly making threats against the Pokemon World Championships had the potential to carry out a mass shooting. That’s according to Police Superintendent Paul A. Fitzgerald, who told reporters this week that detaining 18-year-old Kevin Norton and 27-year-old James Stumbo stopped a “potential tragedy” in the city of Boston.

“We can never read someone’s mind,” Fitzgerland said when asked what the suspects intended to do with their weapons. “What we can read is what they were saying and the actions that they took, bringing the weapons they were showing online as a threat.”

Authorities detained Norton and Stumbo as part of an investigation involving Boston’s Joint Terrorism Task Force, which includes federal agents from the FBI and Homeland Security. The suspects attempted to enter the Hynes Convention Center, the site of the Pokemon World Championships, on Thursday, August 20, but were removed from the premises on a trespass order.

After Norton reportedly made statements to authorities that he had weapons in his car, officers conducted a field interrogation and released them. Police quickly obtained a search warrant and found in their car a 12-gauge shotgun, one DPM5 AR-15 rifle, “several hundred” rounds of ammunition, and a hunting knife.

“That could have been a mass shooting,” Fitzgerald added. “So obviously the federal agencies were concerned with that.”

A news release from the Suffolk County District Attorney’s Office sheds more light on the investigation.

According to prosecutors, Boston Police were notified of a Facebook chat conversation, between Stumbo and others, that made references to things like “Columbine pt 2,” “another Boston massacre,” and “Boston bombing.” As part of this conversation, Stumbo supposedly said, “MY AR-15 says you lose.”

Other posts allegedly made by Stumbo stated that he was “on his way to Boston” and “Kevin Norton and I are ready for worlds Boston here we come!!!” Stumbo also reportedly shared an image of his car with the AR-15 and a shotgun sitting on its trunk.

Prosecutors allege that Norton, in the wake of being blocked from a chatoom for bullying another person, allegedly said, “Oh, ok, that’s fine then I will just shoot him on Friday thanks.”

In a statement on Sunday, The Pokemon Company, which organized this past weekend’s Pokemon World Championships, said it was made aware of the security concern and worked with authorities quickly to sort it out. “Due to quick action, the potential threat was resolved,” it said. “The Pokémon Company International takes the safety of our fans seriously and will continue to ensure proper security measures are a priority.”

Norton and Stumbo, Iowa residents who traveled to Boston for the event, were arraigned in Boston Municipal Court on charges of unlawful possession of a firearm, unlawful possession of ammunition, and unlawful possession of a large-capacity rifle. They are being held without bail. A dangerousness hearing will be held September 1 to determine how the case will move forward.

“The men stood expressionless at their arraignment as authorities laid out the charges against them,” The Boston Globe reported.

Outside of this potential security issue, the Pokemon World Championships were held without issue.