ediscovery criminal investigation

Fitbit Data Provides Clues in Murder Case: eDiscovery & Criminal Investigation

Once again, eDiscovery and emerging data sources are at the center of a criminal murder investigation. A recent article in Wired highlights how investigators used data from the victim’s Fitbit and a neighbor’s Ring digital doorbell camera to establish a timeline, identify a suspect (the victim’s 92 year-old step father), and gain a warrant to search the suspect’s home, all of which led to his arrest.

Similar to other cases involving the use of data from mobile phones, social media, and the Internet of Things, it wasn’t the electronically stored information (ESI) alone leading to the arrest, but instead it gave investigators leads that otherwise wouldn’t have existed in a pre-digital world. These leads then gave them enough evidence to request warrants for further searches and investigations of specific suspects, which then brought about arrests. In other words, solving crimes still boils down to good old-fashioned detective work, only now, investigators have new ways to uncover what might have happened and who may have been involved.

Fitbit first introduced its personal fitness tracking device ten years ago, and today around 27 million people use them. Add that to other competitor’s devices (such as the Apple Watch) and it’s not hard to imagine how investigators often have ready access to biometric data of suspects and/or victims. Last year alone, 170 million wearables were shipped worldwide.

But while much of electronic data is self-authenticating under Federal Rules of Evidence rule 902(14), biometric data gathered from wearable devices is much harder to authenticate as accurate. An analysis of 67 studies on Fitbit’s movement tracking concluded that, “the device worked best on able-bodied adults walking at typical speeds. Even then, the devices weren’t perfect—they got within 10 percent of the actual number of steps a person took half of the time—and became even less accurate in counting steps when someone was resting their wrist on a walker or stroller, for example. ‘It’s not measuring actual behavior,’ says Lynne Feehan, a clinical associate professor at the University of British Columbia and the lead researcher on the paper. ‘It’s interpreting motion.’”

Evidence from fitness trackers has been admitted in homicide cases in Europe and the US, but expert witnesses and analysts are often used in conjunction with the data to authenticate it. Only a few judges have ruled on how to handle evidence from fitness trackers. For example, “In a 2016 Wisconsin case, Fitbit data was used to eliminate the possibility that a woman was murdered by her live-in boyfriend. The judge ruled that an affidavit from Fitbit established the device’s authenticity and allowed lawyers to introduce its step-counting data; at trial, a sheriff’s department analyst vouched for the reliability of the man’s particular device. However, the judge barred the Fitbit’s sleep data, citing a class-action suit that claims the sleep tracking could be off by as much as 45 minutes.”

Similar to older technologies (such as the polygraph), electronically created data isn’t necessarily irrefutable. Antigone Peyton, an intellectual property and technology law attorney who has used data from wearables in civil cases, states that people tend to see “data is equivalent to truth,” but there are “many ways the information on these devices can be interpreted.”

Another aspect that investigators have to consider with this type of data is users’ privacy. Last year, the Supreme Court ruled that police must have a warrant to search phone location data under the 4th Amendment. At times, the companies that have the data, refuse to hand it over to law enforcement if they feel privacy is being infringed upon, but largely, the tech industry seems to cooperate, especially as procedures for handling this type of data are becoming more defined.

What is important for the legal industry to consider is how different types of data and data sources work, and what that means when it comes to authenticating it. It’s similar to when wiretaps, phone data, and other electronic surveillance was introduced into the detective’s toolkit in the 20th century. The difference is the amount of information created today is much greater, and it’s created by every person on a near continuous basis from a large number of sources. And none of this data can be looked at in the same way.

But what this new data does provide is more ways to reconstruct scenes, rule out potential suspects, corroborate or contradict testimony, and gather information which allows investigators to pursue new tactics and lines of questioning which lead to further warrants and arrests. For attorneys, it’s important to stay up on the most recent investigative uses and court-rulings on these data sources, which will continue to define and clarify how ESI is being used in both criminal and civil cases.