Albuquerque police conducted a floor-by-floor search Monday night of City Hall after getting a flood of frantic calls about a possible shooter and hostage situation, but they said there was no evidence any shots were ever fired or that anyone was held against their will.
Authorities set up a wide parameter around the government office complex in the heart of downtown Albuquerque after the first calls for help came.
Albuquerque police spokesman Tanner Tixier said one man was being detained and investigators believed that person was "the initiator" who spurred calls from employees inside the building.
The man, who was not immediately identified, had previous contact with the police department's crisis intervention unit and was known to have issues, Tixier said.
Police had received reports of a man running through the halls and yelling that there was a shooter in the building.
Police believe the situation may have been the result of a hoax, but they were not taking any chances.
"We're going to make sure we do a very thorough and systematic search. We're going to make sure we don't miss anybody in any offices that may be hiding," Tixier said, noting that officers were not working an active hostage situation.
The search of City Hall, which houses both city and county government offices, was expected to take a couple of hours, Tixier said.
Albuquerque police Chief Gorden Eden was at the scene along with Bernalillo County Sheriff Manny Gonzales.
Employees were escorted away from the building by officers in tactical gear. No injuries were reported.