While the whole country is relieved that this past week’s Boston Marathon bombing ordeal and subsequent lockdown of the city is finally over, Boston Police Commissioner Edward Davis told the Washington Post that the department’s facial recognition system “did not identify” the two bombing suspects.

“The technology came up empty even though both Tsarnaevs’ images exist in official databases: Dzhokhar had a Massachusetts driver’s license; the brothers had legally immigrated; and Tamerlan had been the subject of some FBI investigation,” the Post reported on Saturday.

Facial recognition systems can have limited utility when a grainy, low-resolution image captured at a distance from a cellphone camera or surveillance video is compared with a known, high-quality image. Meanwhile, the FBI is expected to release a large-scale facial recognition apparatus “next year for members of the Western Identification Network, a consortium of police agencies in California and eight other Western states,” according to the San Jose Mercury News.

Still, video surveillance did prove extremely useful in pinpointing the suspects.

“The work was painstaking and mind-numbing: One agent watched the same segment of video 400 times,” the Post added. “The goal was to construct a timeline of images, following possible suspects as they moved along the sidewalks, building a narrative out of a random jumble of pictures from thousands of different phones and cameras. It took a couple of days, but analysts began to focus on two men in baseball caps who had brought heavy black bags into the crowd near the marathon’s finish line but left without those bags.”

Authorities released official images to stave off Reddit

The Post also cited unnamed “law enforcement officials” who lambasted the use of Reddit and other social media sites that were attempting to work in parallel to the authorities.

“In addition to being almost universally wrong, the theories developed via social media complicated the official investigation, according to law enforcement officials,” the Post reported. “Those officials said Saturday that the decision on Thursday to release photos of the two men in baseball caps was meant in part to limit the damage being done to people who were wrongly being targeted as suspects in the news media and on the Internet.”

On the science side, two Boston medical researchers called for a special autopsy test to look for the presence of chronic traumatic encephalopathy (CTE), a boxing-related brain disease. Some wonder if the older brother, Tamerlan Tsarnaev, could have been affected by the disorder due to his history as an amateur boxer. According to this theory, damage from the sport could have led him towards erratic behavior and violence.

But according to the Boston Globe, those same researchers were extremely cautious. Even if medical examiners did find the presence of CTE, it would not be proof positive of a causal link to violent and extremist behavior.

“Is it possible that some changes might have gone on in his overall functioning due to his boxing and potentially related brain disease? Yes,’’ said Dr. Robert Stern, a co-founder of the Center for the Study of Chronic Traumatic Encephalopathy at Boston University, in an interview with the Globe. “Anything is possible. But to then jump to the disease leading to well-planned behavior like this? I couldn’t go there.’’