In a dramatic week in Boston after the bombings on April 15, the teenager known as Suspect No. 2 was captured on Friday evening with the aid of some advanced technology.
There's no doubt that technology played a big part in the investigation of the marathon bombings. Crowd-sourcing, CCTV, thermal imaging cameras — all were used in the investigation that led to the death of one suspect, Tamerlan Tsarnaev, and the capture of his brother, Dzhokhar.
One tool, the widespread use of surveillance video in public areas, has proven crucial elsewhere, says Thomas Ruskin, president of the CMP Protective and Investigative Group and a former New York City detective.
In an interview on CBS.com, Ruskin spoke about the 2005 bombings in London, which killed 52 people and injured almost 800: "London has the best surveillance in CCTV systems in the world. London Police and Scotland Yard could almost immediately identify each person who got into the bus and subway system."
But the use of technology by nonprofessionals might lead to unintended or even tragic consequences, says Alexis Madrigal, senior editor of The Atlantic and the author of "Powering the Dream: The History and Promise of Green Technology."
"Vigilantes have organized themselves on Reddit for a manhunt. They want justice served," Madrigal wrote as the manhunt was underway. "And they're openly debating suspects on the site. They're gonna solve the case! Like real cops on television. But they are not real cops. They are well-meaning people who have not considered the moral weight of what they're doing."
Reddit's general manager, Erik Martin, apologized, sort of, in the aftermath without saying exactly how the site would do things differently in the future.
In this case, the technology raises vexing questions for future investigations.
"It is an object lesson in how hard it is to separate the meaningful from the noise in a world awash with information," according to the Washington Post.
"The killing of Tamerlan Tsarnaev and the capture of his younger brother, Dzhokhar, may seem like an inevitable ending given that their images were repeatedly recorded by store security cameras and bystanders' smartphones. But for 102 hours last week, nothing seemed certain in the manhunt that paralyzed a major metropolis, captivated the nation and confronted counterterrorism operatives with the troubling and unforgiving world of social media and vigilante detective work."
In the end, the events in Boston led to "what may be the world's most crowd-sourced terrorist hunt," according to NBCnews.com.
"It's not the first use of private video from stores or other places to help solve a crime. That is a common investigative technique," said Jim Bueermann, president of the Police Foundation and former police chief of Redlands, Calif. "But it is without a doubt the largest-scale use of crowd-sleuthing that I've seen."
THE TAKEAWAY:"Suspicious types" or stereotypes?
Host Tom Weber asked Madrigal whether the crowd on Twitter or Reddit actually got anything right in the search for the perpetrators of the Boston bombing. Madrigal replied, "Well, you know ... no. I think you got a lot of misidentifications, really fast."
"And Reddit never identified the correct suspects before they were identified by the FBI, is that correct?" Weber asked.
"That is right. And even after the photos came out, they also did not correctly identify the names of the people," Madrigal said.
He added that the crowd poring over photos tended to finger people of color as looking suspicious.
"When you don't have access to all the information," he said, "when you're not a professional investigator, when you don't know what you're looking for, what you do is pattern matching of people who 'look suspicious.' And that ends up being people who just don't look like you expect them to. It's no surprise that in a lot of these cases the people who were identified were not Caucasian people. People were like, 'Hey — who are the suspicious types?' And when they passed it through that particular filter, they came out the other end fingering 'suspicious people' who happened to have darker skin."
MORE FROM MPR NEWS:
• How to keep crowds safe at large events
In the aftermath of the deadly bombings at the Boston Marathon, security is being beefed up at sporting events across the country.
• Photos: Manhunt in Massachusetts for Boston Marathon bombing suspects
The hunt for the suspects last week.
• Today's Question: Should we be crowd-sourcing investigations like the Boston Marathon bombings?
Read answers from others and leave your own.