Evans said the man called back a few minutes later to say he was armed and that he had shot a hostage.
The school sent an alert warning students to stay away from the library at 771 Commonwealth Ave as police searched the building.
“It was a phone call, and we were on the line with the individual, so we treated it like it was the real deal,” Evans said. “It was so detailed that we had to take it serious.”
BU spokesman Colin Riley said police evacuated the library and student union.
“It was not a robocall. It was an actual person on the other end of the line answering questions,” said Boston University Chief of Police Scott Pare, adding that the caller identification was blocked.
The area was cleared after determining that the threat was a hoax.
“What we practiced last month in a drill — actually in the same, exact building — it worked, unfortunately, perfectly for us with Boston police, State Police and Brookline police all showing up,” Pare said.
Officials said the caller had an accent, and they are working to trace the hoax call.
