For 18 minutes Saturday morning, the person claiming there was a gunman at MIT described the fictional threat using a Sprint messaging service for people with hearing or speech impediments. The messages named an MIT employee as the gunman – claiming his motive was retaliation for the death of Internet activist Aaron Swartz – and naming MIT President Rafael Reif as the target.

Cambridge Police Commissioner Robert Haas said it didn’t take long for authorities to realize the MIT staff member identified as a gunman was not involved.

"It was very malicious," Haas said. "It was maligning the character or person. Clearly, the person was identified very quickly and identified that he was not involved. I think it was very vicious in terms of the way the message came across -- and the details."

Haas said the Middlesex district attorney has issued a subpoena to Sprint for the IP Address of the computer that sent the bogus messages. Meanwhile, MIT is promising to issue emergency notifications more quickly in the future. The school has been criticized for waiting nearly an hour and a half to issue a campus-wide alert. By contrast, it took just seven minutes for the Cambridge Police Department to tweet about the report of a gunman. That’s because four days earlier, the department launched an automated Twitter program developed by communications director Dan Riviello.

"Had this been a real incident, our followers would have known within minutes that something was going on -- that there was a person with a gun -- and if even one person then decided to stay in their dorm room or avoid that area, that’s one more life that we could have saved," Riviello said.

The tweets go out automatically – minutes after dispatchers enter the crime reports in their computers, alerting the public whether it’s a false alarm or the real deal.