AUBURN — Police swarmed Great Falls Plaza early Thursday night after a man was reported wandering with a gun at the Hilton Garden Inn.

When Auburn police went to the scene at about 6:30 p.m., it was not clear whether the gunman was inside or outside the hotel. Officers set up a perimeter around the building while trying to collect further information from witnesses.

Lewiston police went to Longley Bridge, standing by in case the situation escalated. For a time, police considered evacuating the hotel while the situation was investigated.

At about 6:45 p.m., a witness gave police tentative identity of the gunman. Soon after, they recovered a clip from a 9-millimeter handgun and learned that at least one suspect had headed outside.

Auburn police officer Matt Daley was watching the rear of the building when he spotted a man leaving through a back door, according to police Lt. Scott Watkins. The man identified himself as Joseph Boothby of Auburn and admitted he had a gun, Watkins said.

Boothby and another man were handcuffed and questioned. Boothby was arrested on a warrant unrelated to the incident at the hotel, Watkins said. He was still being questioned late Thursday night.

“We’re still investigating what he was doing with the gun and why he had it at the hotel,” Watkins said.

The lieutenant said nobody was threatened during the incident.

Shortly after 7 p.m., police advised hotel management that the situation was under control. The hotel was not evacuated, but police secured one room as they began the investigation. They remained there late Thursday night.