In major cases like the Paris terror attacks, cyber fingerprints are becoming increasingly critical and helpful elements of intelligence work, said Jon Rajewski of the Leahy Center for Digital Investigation at Burlington, Vermont's Champlain College.
"This is a very complex puzzle," Rajewski said of the Paris investigation. "Cyber investigators, digital forensic investigators typically play a role in the investigation - they're not the magic wand that finds the smoking gun every single time. It truly is looking through a haystack for that one little needle that is the evidence that helps, maybe, bridge the gap between what happened and what didn't happen."
The attacks on Paris left 129 people dead and many more injured.
Rajewski told necn he believes law enforcement is surely turning to digital analysts to help track relationships between the suspected attack planner, Abdelhamid Abaaoud, and any associates of his they can find, perhaps through cellphone geolocation or social media use. The prime challenge, Rajewski noted, will be that messages are so often encrypted.
"This isn't easy to investigate," he said of the digital world. "The complexity of digital data-- it's evolving every day; new apps get pushed every week. To investigate this actually takes time and expertise."
Rajewski added that even if police cannot always read the content of specific notes between persons of interest in cases, it is still sometimes possible to use data from cell providers or internet hosts to uncover a general link between two parties, then let old-fashioned police work take over and trace targets' travel and interview witnesses.
"The actual crime itself happens in the physical world, but all the planning and the tactics - all that stuff that happened prior--is typically in some sort of digital record," Rajewski explained. "If you have access to the records, hopefully you can figure out what happened. Now, getting legal access to that data in different countries means different things."
According to the Associated Press, Sen. Richard Burr, R-North Carolina, said Tuesday it was likely the attack plotters in Syria, Belgium and France used encryption to hide their communications from authorities. Sen. Dianne Feinstein, D-California, endorsed Burr's comments.
Knowing digital communications would be a major investigative tool after the shocking violence in Paris has renewed the debate in this country over the line between digital privacy and national security.
John Brennan, the director of the CIA, addressed that issue Wednesday at the 30th annual briefing of the U.S. State Department's Overseas Security Advisory Council in Washington.
"There is a great debate about what the government's role is in that domain, and there should be that debate about what we need to do to balance individual rights and civil liberties, and what is the appropriate role for government in that domain in order to protect its citizenry," Brennan said.
In that speech, Brennan noted intelligence agencies globally have many successes, and that a terror attack would only "redouble" the determination of security professionals.
"Every day around the globe, law enforcement and security intelligence agencies are taking actions that disrupt the plans, intentions and activities of these terrorist organizations," Brennan told the council. "Unfortunately, some get through."
Rajewski predicted the conversation over tensions between civil liberties and granting investigators more access to encrypted digital conversations will continue to pick up intensity on Capitol Hill.