NEW HAVEN, Conn. -- After the school massacres at Sandy Hook, Virginia Tech and Columbine, this has become, perhaps, the inexorable consequence of any threatening phone call.
At Yale University, hours after an anonymous man called and warned a dispatcher that a gunman was headed to the school to "shoot some people," a campus lockdown was lifted Monday afternoon after police scoured the campus room-by-room without finding a would-be killer.
There were no reports of shots fired. At a news conference before the lockdown was lifted, investigators had begun to suspect that a witness who reported seeing someone with a gun may have seen a police officer.
But doubt alone was not enough to call off a search. On the same day investigators elsewhere in Connecticut released a lengthy report on the school shooting that happened last December just 25 miles away -- the massacre at Sandy Hook Elementary School in Newtown -- officials had no second thoughts about continuing to send armed teams to search the rest of the Yale campus after part of the lockdown was lifted.
“In this day and age, when there is a call, it behooves us to overreact and not underreact," New Haven Police Chief Dean M. Esserman said at a news conference. “We don’t have the luxury of going on a hunch."
The anonymous call lasted just a few seconds. Esserman described it as "malicious."
Officials said a man in a public phone booth, speaking in a matter-of-fact tone, said a "roommate" was on his way to campus to go on a rampage. And then the man hung up.
Investigators puzzled over the call, but alarm was further raised by reports that at least one witness had seen someone with a gun on or around campus.
Yale was placed on lockdown, and a now-familiar scene of SWAT teams creeping through an eerily calm campus played out in front of news cameras and students with cellphones awaiting the all-clear.
The chilly campus was empty and silent. People gathered to watch the police and walked casually around the edges of campus, where officials had blocked off several blocks.
"We're going to be here til midnight," one police officer said wearily to another before the lockdown was lifted. He read out an update on SWAT activity and helicopters buzzed overhead.
John Maheswaran, 22, a Yale senior who lives off campus, had been watching police near the Old Campus area at the northwest end of the green since morning. He said three SWAT teams of officers carrying long guns arrived on High Street a few hours after the first reports of a gunman.
"It feels very weird. I can't believe it's happening here," Maheswaran said. "Campus is incredibly safe. It makes me a bit nervous."
Officers in green army-fatigue-like outfits and helmets headed toward Old Campus. Sebastian Munos, 27, who mans a burrito cart on the edge of the lockdown area, said police had been gathering since morning and that students had seemed to be heeding police instructions to stay inside.
A Yale alert to students said that "out of an abundance of caution," police would conduct a room-to-room search of Yale dormitories, sometimes sliding their IDs under the locked doors of occupied rooms. The alert said police would enter dormitories if students were not home.
Tom Conroy, spokesman for Yale, said thousands of people remained on campus despite Thanksgiving break. It took about half an hour after the 911 call at 9:48 a.m. for Yale to send out its first alert at 10:17.
Conroy said the initial call went to New Haven police, not Yale, and that Yale mobilized its emergency resources immediately.
By 3:30 p.m., with four SWAT teams said to be conducting the searches, the lockdown had been lifted across campus except for the university's Old Campus area.
Esserman said investigators didn't think the caller or his so-called roommate were Yale students, and he promised that the hunt would continue.
"We’re going to find the person that made that call, and we’re going to put handcuffs on the person that made that call," Esserman said.
Agencies including the Connecticut State Police, the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives responded to the scene, joining campus and New Haven police in carrying out the search in near-freezing weather.
“I imagine we’ll be buying our officers dinner tonight," Esserman said.