Former Boston Police Commissioner Ed Davis, who was a key figure during the search for the Boston Marathon bombing suspects, said the massive search for the gunman in a deadly shooting at Brown University on Saturday is an "all-hands-on-deck" situation.

Providence Mayor Brett Smiley said Saturday during a news conference that at least two people were killed and nine more hospitalized following a shooting at the university in Providence, Rhode Island.

As of Saturday night, no shooter is in custody and a massive manhunt is underway in the area with police departments from throughout the region on hand. The FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives are responding to the scene.

Police released a surveillance video that they say showed the gunman walking in the area. Their face was not visible. 

Ed Davis on Brown University shooting

In 2013, three people were killed when bombs went off near the Boston Marathon finish line. Four days later, Office Sean Collier was killed during the manhunt for the suspects. Officer Dennis Simmonds died a year later from injuries he suffered during a confrontation with the bombers.

Davis, now a security analyst, spoke about what it is like to coordinate such a massive police response like what unfolded in Boston in 2013 and at Brown University on Saturday.

"I'm just talking about the way that I did business, but it really is crucial that you have a good team at the top of that pyramid to make decisions," Davis said. "We had FBI agents, state police, we had secret service agents who were providing us with armored cars. Everybody came to the scene and said 'How can I help? What do you need?' And that's exactly the kind of attitude that you have to have in a situation like this. It's one fight, everybody's in on it, and nobody is standing up trying to take credit. It's all hands on deck."

Search for Brown University shooter

Davis said one challenge police faced Saturday night is that it was a frigid December night.

"Very difficult, tense situation. Very dangerous for the officers, and I'll say very dangerous for the community members who live in that area," Davis said. "Some of these individuals who are on the perimeter were dressed for the normal night in a police cruiser, not dressed to stand outside in 30-degree weather. So all these logistics issues, to say nothing of the psychological impact of these things, there's a lot to consider in the next 24 hours here."

Davis said investigators are likely using a variety of tactics to locate the suspect, including cellphone towers and surveillance cameras.

"People are afraid"

Brown University was placed in lockdown, and people have been urged to lock their doors and not go outside. Davis said this is critical at a time when police did not know where the gunman was.

"People are afraid. The best thing they can do is to follow the advice of the public officials. If you're sheltering in a dormitory somewhere, get on the phone with a trusted relative or someone who can talk you through the situation," Davis said. "It's extremely unsettling. But as long as you're safe behind a locked door and you don't do anything to bring attention to yourself, you just want to try to wait it out. It's helpful to have somebody counseling you through a situation like that."