For many, the first images of the Boston Marathon bombing -- a cloud of dark smoke rising up over Boylston Street -- came from Twitter or Instagram. The FBI received thousands of hastily snapped photos as they hunted the culprits. But does a camera in every pocket actually make snaring criminals any easier?
"The Internet is a force multiplier," Lenny DePaul, the retired former chief inspector of the U.S. Marshals service, told NBCNews. "We can't knock on one million doors, so the speed of the Internet is a major advantage when it comes to sharing information."
The new age of social-media tips may seem worlds away from the seasoned cop on the beat -- but it's become another trove of potential clues to be used in all sorts of investigations.
Richard DesLauriers, who was the Boston FBI's Special Agent in Charge at the time of the bombing, told NBCNews the popularity of personal gadgets and the Internet “means a wider range of people who have the ability to help law enforcement.”
DesLauriers, now a vice president for security at Penske Corp., made use of the new media landscape in the hunt for both the bombing suspects and gangster Whitey Bulger.
Immediately after the bombing DesLauriers specifically appealed to the public to send in photos, videos and any other information that might be relevant. As a result, 120 FBI agents sorted through more than 13,000 videos and 120,000 photos in the days after the bombing.
"Collecting as much evidence around the scene of a crime is the first thing you do in trying to identify individuals, and video is often the most compelling evidence," DesLauriers told NBCNews.
A video was indeed the "eureka moment" in the Boston Marathon bombing case, DesLauriers said. But it didn't come from one of the thousands of video clips civilians sent in.
Instead, it was more traditional police work. Among other considerations, an eyewitness account from bombing victim Jeff Bauman -- who lost both his legs to the sideline explosives -- helped investigators comb through the hours of video. Bauman had locked eyes with the man who eventually became a prime suspect: Tamerlan Tsarnaev. Eventually, investigators found a clip from a surveillance video that they believed showed at least one suspect.
"That video was instrumental in assisting us," DesLauriers said. "We didn’t know identity at the time, but we had the visual image we needed."
The most effective use of social media for police work might not be in gathering clues, but as a tool to keep the public up-to-date on the latest information, according to a new report from the Harvard Kennedy School and co-authored by former Boston Police Commissioner Edward Davis.
Twitter and other social platforms were effective, the report said, because law enforcement had been using them for both major crimes and the average incidents that occur in every city daily.
"Years ago, moving a public statement on a major incident such as a homicide was significantly time-intensive, requiring interoffice memos as well as the writing and screening of statements,” the Harvard report said. "The use of social media allows the police to push information to the public directly and instantaneously."
The openness of social media also means the police can get a flood of information -- tweets, videos, Instagram photos -- from well-intentioned citizens, amateur gumshoes, and cranks alike. The likelihood is that the vast majority of those bits and pieces won’t add up to a clearer puzzle.
"When you get thousands of messages that are potential leads, you need to exhaust all possibilities," said DePaul, the former U.S. Marshals chief inspector. "It can work against you because it takes up a lot of time."
The public has nonetheless played a role in solving several major crimes, from the D.C. sniper case in 2002 to the media campaign that ended the nearly two-decade search for Bulger.
But, DesLauriers acknowledged, "a counterterrorism investigation like the marathon is quite different from a fugitive search."
Maki Haberfeld, a police science professor at the John Jay College of Criminal Justice, said crowd-sourcing crime is best suited to specific types of investigations.
"Social media makes sense in extreme situations, a quick and active response like the Boston case," Haberfeld said. "But it doesn't lend itself to all situations."
In the end, DePaul said, people on the ground are still what make or break cases.
"We can't be everywhere, though we try," DePaul said. "Even with cameras up at every bank and 7-Eleven, you just can't beat the aid of the people."