BOSTON (MyFoxBoston.com) -- During the Boston Marathon bombing and the weeks that followed, one man was instrumental in keeping Boston safe.
Ed Davis was our city's police commissioner at the time. He's talked with us many times about that day and what the men on his task force and city endured. One year later, Ed Davis shared his reflections.
The 2013 Boston Marathon was the seventh Davis had been involved in. He said he started the day reviewing the operational plan.
Davis was on a conference call with the White House when Superintendent-in-Chief Dan Linskey called to tell him what was transpiring at the scene.
"Well I first thought that maybe it was electrical in nature, that maybe something in the environment had, had gone off. A gas explosion or an electrical explosion," said Davis. "But as I talked to Dan, very quickly I formed a different opinion."
Davis described the telephone call, saying officers could be heard yelling for help on radios in the background.
"Very quickly in the conversation, Dan said that one of our sergeants had requested all the ambulances that we could get and he said that there were multiple amputations," Davis recalled.
The former commissioner said he formed the opinion that the event was most likely a terrorist attack after learning there were multiple amputations.
"The other things that came to mind were the fact that there were two explosions, in close proximity to each other in time and distance. All of those things made me believe that, that it was most likely a planned terrorist attack," said Davis.
Davis said there was concern about the possible existence of a third device.
"It's very, very common for Al-Qaeda to strike in three different strikes," Davis explained. "And we felt, when we responded to the scene, that there would be a third device."
The first calls Davis made were to FBI and Mass. State Police officials to assemble as many response teams as possible in the area of the blasts. He arrived to the site of the second explosion at about 3:10 p.m. to find the bodies of two of the three victims.
"I could also feel shrapnel underneath my feet," Davis described. "I could tell that the bomb had been designed to hurt and maim people. So then I ran down to, to the scene of the first explosion and that was very similar scene, but it looked like the bomb was actually more powerful there. The explosion had gone up two or three stories."
He said the scene looked like a battlefield and was similar to photos and video from bombings in the Middle East that police officials looked at during training.
After clearing packages that had been abandoned at the scene, investigators began gathering evidence.
"It was clear to me that with the proliferation of cell phone video that there was not a place in that area that wasn't documented by someone," said Davis. "So we concentrated on downloading all sources of video, whether it be businesses that had security cameras, whether it be people in the crowd; and very quickly we went on social media and asked for help in downloading any video or still pictures that people had."
Investigators focused in on cameras that were closest to the scene. Citing a pending trial, Davis couldn't get into much detail about the photos, only saying officials in Washington gave them permission to publish the photos late in the day Thursday, April 18.
Hours later, Davis learned MIT Police Officer Sean Collier had been fatally shot. Initially, investigators believed his murder was connected to an armed robbery. They didn't know there was a direct link to the bombing investigation until later in the night.
"Well Officer Collier really was the first line of defense against two individuals who had not only killed and maimed hundreds of people, but were intent upon continuing their rampage," said Davis, who also called Collier a hero.
Collier was shot while sitting inside his patrol car. Citing an ongoing investigation, Davis said he didn't know what happened prior to the shooting. When asked if there was surveillance video from the scene, Davis said he believed there is.
It was previously reported that the accused Marathon bombers carjacked a Cambridge man after the fatal shooting. The man was able to escape the car at a local gas station and call police. Davis said that call was a huge turning point in the investigation.
"Dan [Linskey] called me back around mid- a little after midnight and said that he was engaged in a motor vehicle pursuit where suspects were shooting at the officers and throwing bombs," said Davis.
Davis immediately responded to the scene in Watertown.
"What struck me first was the fact that they had not fled. I really believed that they had probably committed the act and fled the jurisdiction to a different country. I didn't expect that they would stay around. So in some ways I was, I was surprised that they were still here, but I was happy that we were going, that we were on them and most likely gonna capture them," Davis said.
Davis praised the work of the responding officers in Watertown, including the coordination and tactical efforts by Sgt. Jeffrey Pugliese.
Accused Marathon bomber Tamerlan Tsarnaev died during a shootout with police after he was run over by a car driven by his brother, Dzhokhar Tsarnaev. Dzhokhar was found hiding in a boat in a Watertown backyard hours later.
"You know, on what happened in the boat, it's all part of a Massachusetts State Police investigation and I really can't get into the details of it," Davis explained. "But something happened there to cause the officers to fire; and ultimately, thankfully, the fire was controlled before anybody was hit."
Davis praised what he described the "unprecedented collaboration" among law enforcement agencies both on the state and federal level.
"The bottom line was this whole 'Boston Strong' mentality really played itself out among the law enforcement agencies; but most importantly among the community," Davis said. "The community was there to help us every step of the way, and if it wasn't for them we wouldn't have caught this guy. So it was a great example of community policing and Boston Strong."