IT seems as if every week there’s a news story about someone committing a crime and confessing to it on Facebook, bragging about it on Twitter or sharing photos of it via Instagram. In many ways, social media has been a boon for law enforcement, handing the police ready admissions of guilt, equipping criminal investigators with new types of evidence and empowering prosecutors to better dispel reasonable doubt of guilt.
In a recent Delaware case, for instance, prosecutors were able to push for an increased sentence for an 18-year-old woman convicted of vehicular manslaughter after they found photos and comments on her MySpace page glamorizing alcohol abuse. In another case, in Las Vegas last year, locational information tied to tweets enabled the police to find potential witnesses to a fatal shooting. And in a 2012 case, a victim of armed robbery in Texas identified his assailants through publicly available Facebook photos.
But legal scholars, judges and ethicists say that social media is also creating a range of new challenges for law enforcement. In some cases, the flood of digital information has overwhelmed investigators. False tips, now easier to submit anonymously, send the police on more wild goose chases. Meanwhile, these new types of evidence are forcing judges to make tough calls about how best to ensure impartiality and what limits to put on jurors’ free speech rights.
“We all have a Fifth Amendment right not to incriminate ourselves,” said Lori B. A...