When Ross Compton had a pacemaker installed, he had a constitutional right to remain silent. One would expect his body to have the same. But when the 59-year-old's Middletown, Ohio, home erupted in flames last September, the electronic data stored in his cardiac device eventually led to his arrest and subsequent indictment on charges of arson and insurance fraud. And despite his attorney’s arguments to the contrary, earlier this month Butler county judge Charles Pater held that the functioning of Compton’s own body — heartbeat included — could be used against him at the upcoming trial.

WIRED OPINION ABOUT Deanna Paul (@thedeannapaul) is a former New York City prosecutor and adjunct professor of trial advocacy at Fordham University school of law. This fall she will begin attending Columbia University’s graduate school of journalism. Her nonfiction work has been published by Rolling Stone and The Marshall Project.

In September 2016, Compton told law enforcement, he awoke to find his home on fire; he survived, but the blaze caused $400,000 of damage and killed his cat. Before escaping, Compton managed to pack his belongings in multiple bags, grab his computer and medical device charger, break through a window with his cane, and throw his luggage out of it. Then, he abandoned the feline and fled.

Ohio authorities determined that the fire originated from multiple locations within the house, leading them to conclude that a crime had occurred. They said statements Compton gave to fire officials at the scene differed from the story he later told investigators; in addition, investigators reported Compton's property smelled of gasoline and that his account was inconsistent with the available evidence.

Once police learned about Compton's pacemaker, the department decided to obtain a search warrant for the data recorded on it; this would reveal his heart rate and cardiac rhythms before, during, and after the fire. Medical technicians downloaded the information (the same information that would routinely be retrieved from a pacemaker during a doctor's visit) from the device, and law enforcement subsequently subpoenaed those records from the hospital.

The information corroborated one version of events, investigators argue. Unfortunately for Compton, it wasn’t his.

Ohio authorities alleged the data showed that Compton was awake when he claimed to be sleeping. In addition, investigators stated that given Compton's medical condition and the few minutes that passed between the time Compton called 911 and police arrived on the scene, it was improbable that he would have been able to collect and remove his belongings and himself from the burning house so quickly.

This was, the involved parties agreed, the first case in which police obtained a search warrant for a pacemaker. Compton’s defense attorney, Glenn Rossi, filed a motion to suppress the pacemaker data evidence as an unreasonable seizure of Compton’s private information. Nevertheless, in court assistant prosecutor Jon Marshall argued that police have historically obtained personal information through search warrants and that doing so for a pacemaker should not be viewed differently. The trial is scheduled for December.

Law enforcement can use legally obtained blood samples and medical records as evidence. Investigators have also recently used data from less invasive smart devices, such as steps counted by activity trackers and queries made to speakers, to establish how a crime was committed. In Connecticut, Richard Dabase was charged with murdering his wife after police built a case based, in part, on the victim's Fitbit data. In Arkansas, James Bates was charged in the death of his coworker. After noticing an Amazon Echo smart speaker in his kitchen, investigators requested a search warrant for any audio recordings and data from the device.

In Compton's case, it may seem unnerving that information contained inside the body — as opposed to kept in the home or worn on the wrist — could be used in a criminal investigation. But courts have yet to distinguish between data interior to the body and data stored on the outside. Data isn’t considered more protected or more private by virtue of its personal nature or where it is stored.

The more connected, convenient, and smart our devices are, the more they have the potential to expose the truth. “The reality is that we are no longer the sole proprietors or controllers of our personal information,” says Stephanie Lacambra, the Electronic Frontier Foundation’s criminal defense staff attorney. “For people worried about being monitored in that way, this ruling is chilling. If Compton didn’t want doctors and law enforcement to have access to his heartbeat, what alternative did he have — decide against getting a pacemaker?”