“I don’t know, Andy. People know that their cell phones send signals to cell towers.”
“Yeah, but do they know that the cell towers keep records of those pings down to the minute and second and store them for years? Do people know that we can draw on historical CSLI to trace someone’s movements years later?”
“The only question is whether Simon Dobias does,” she says. “And I’ll bet the answer is yes.”
79
Simon
“Happy Wednesday, all, and happy November,” I say to the class. “Hope you all had a nice Halloween and a day of recovery yesterday. Let’s get to it.Carpenter versus United States, a case that best can be summarized as boy-is-it-scary-what-the-government-can-do-to-us.”
That gets a laugh. I try to keep it light.
“Cell phones,” I say. “No longer just mechanisms to make calls or shoot a text message. No longer simply little computers to search the internet or monitor your daily step count or play Spotify. Cell phones are now tracking devices, too. As the unfortunate Mr. Carpenter learned, cell phones allow the government not only to surveil your movements contemporaneously but also historically, going back years.
“Your cell phone is always working, even if you’re not using it, if for no other reason than to refresh and receive new text or email messages. It always seeks the nearest cell tower for a connection. And each cell tower then records that connection and memorializes it, stores it, down to the day, hour, minute, and second. So if the government has your cell phone number, they can go back and subpoena those cell-tower records—called cell-site location information, or CSLI—and retrace your steps. Not just the calls you made. Not just the text messages you sent. But every place you walked. Every place you drove. And exactly, down to the second, when you did so.
“In a nutshell, the government can go back in time and know, within a reasonable approximation, every place you’ve been and when. Unless, of course, you’ve turned off the phone. But how often do we dothatthese days?”
(Sometimes. Sometimes we do.)
“The government suspected Mr. Carpenter of robbing a series of stores over a four-month period. They received historical CSLI for his cell phones during that period. They came up with almost thirteen thousand location points for his movements during that period—or about a hundred per day. They were able to map out his movements and place him at or near the scene of four different robberies at the time they occurred.
“But did they violate his rights? That was the controlling question inCarpenter: Does the Fourth Amendment require a warrant for the government to access this highly valuable but highly private cell-site location information?”
—
When the afternoon class is over, I return to my office. I open up theChicago Tribunefor today—Wednesday, November 2—and reread the article on page three:
POLICE PROBE DEATH OF GRACE VILLAGE WOMAN
The wife of a prominent hedge-fund investor was found dead in her home Tuesday morning in the western suburb of Grace Village in what authorities are calling “suspicious circumstances,” though Grace Village police chief Raymond Carlyle said there was no reason to believe that others in the community were at risk.
The Cook County medical examiner’s office identified the victim as Lauren Lemoyne Betancourt, 39, who lived with her husband, Conrad, 54, in a home in the 1000 block of North Lathrow Avenue. They had no children together.
Carlyle said police were called to the home at approximately 7:30 a.m. Tuesday morning after Mrs. Betancourt was found dead by an individual who cleaned the Betancourts’ home.
“Preliminary information gathered at the scene indicates that the death occurred under suspicious circumstances,” Carlyle said in a written statement released by the Village. “However, none of the injuries appear to be self-inflicted.”
Not self-inflicted? Depends on how you define that term, I guess.
I scoop the paper up, walk down the hall, and drop it into a garbage can. I feel a bit guilty about not recycling, but I’ve done worse.
I’d love to go online and read more about the current updates. I’m reading an article published in this morning’s paper edition, meaning it was written last night, Tuesday night. And now it’s late afternoon on Wednesday. I can only imagine what they’ve found since then.
But I can’t check. Searches I do on my phone or computer are discoverable. So I’m stuck with archaic newspaper reports, stale as month-old bread by the time I read them.
My cell phone buzzes. I don’t recognize the number.
“Hello, this is Simon.”
“Simon? This is Jane Burke. I’m a sergeant with—”
“Jane Burke? From Grace Consolidated?”
“—Department.”
We talked over each other. I know who she is. I know where she works. I didn’t know if she’d catch the case, but she was as likely as anyone. It’s not a huge police force.