Prosecutors Forget the “Forgetting Curve” When It Comes to Emails

By Sara Kropf

I was sitting in a proffer a few days ago when they were asking my client about emails sent a few years ago. It occurred to me that prosecutors have a truly peculiar view of email. That’s not a big deal until you realize that they use their oddball perspective to prosecute people for crimes.

Most of my clients are executives who work in white-collar professions. These industries naturally involve a lot of emails—health care, insurance, government contracting, and the like.

We all get a lot of emails. Apple’s Tim Cook said in 2014 that he received 700 to 800 emails a day. Virgin Group’s Richard Branson receives 400 emails a day. One report estimates that the average worker in 2019 sent and received 126 emails a day. Those numbers go up every year.

Let’s assume my client is not Tim Cook but is a bit more average. He receives, say, 100 emails a day. If there are about 20 workdays a month, over five years, then, my client receives around 120,000 emails.

That 120,000 number doesn’t include texts, Slack or WhatsApp messages, and other communication channels. That number also doesn’t include email attachments. Of course, some emails contain no attachments and others contain several attachments. Some of those attachments are long documents, some are multi-sheet Excel spreadsheets, some are detailed PowerPoint presentations.

That’s a lot of documents over a five year period. How well can someone remember them?

Not well.

The Forgetting Curve

There is a compelling scientific theory called the “forgetting curve.” This is a fairly basic (and commonsense) theory that memories fade over time. In the late 1800s, a German researcher named Hermann Ebbinghaus conducted a rather unscientific study (on himself!), testing how long he could remember a series of nonsense words. He graphed those results in a “forgetting curve.” Here’s a simple depiction of the curve:

Now, this isn’t some crackpot theory—like, you know, bite or hair analysis. It’s been replicated many times using real scientific methods. A 2015 study offered a “a successful replication of Ebbinghaus’ classic forgetting curve from 1880” and showed that that data “most probably shows a jump upwards starting at the 24 hour data point.”

In other words, after 24 hours, memories fade considerably.

The Forgetting Curve after Five Years?

Look at the graphic of the forgetting curve. After just a week, your retention of information is down around 10%. Imagine where it is after a few years. Likely around zero, right?

Prosecutors may not know about Ebbinghaus or the forgetting curve, but they should understand the concept that people don’t remember minor events several years later. They should understand the concept well enough not to penalize someone who does not remember an email from five years ago.

If they understand this concept, they regularly ignore it in two key ways.

First, prosecutors think that people remember every email they have ever received. During a proffer session, a prosecutor will ask whether my client saw a draft document. My client will say, quite reasonably, “I don’t think so.”

The prosecutor will slap down an email that attaches a draft document, with a smug look. “Now, do you remember that you saw a draft of that document?” Many times, my client still has no clue whether he saw that document or not because no normal person remembers every email he receives.

But the prosecutor is always quite sure that my client remembers one email of those 120,000. And she’s sure that my client is lying when he says he doesn’t remember it. It makes zero sense when you think about it. If a prosecutor does not believe my client is telling the truth during a proffer session, the chances of that prosecutor indicting my client go way, way up.

Second, prosecutors think that people read every email they receive (and remember what’s in the email). It’s the same dynamic. The prosecutor is certain that my client has read every email he receives and also has read every attachment to every email. “Did the CFO suggest that Acme Corp’s 10K include misleading revenue numbers?” she asks. “I don’t think so,” says my client.

Another email slapped down. This time, the subtle (or not so subtle) implication by the prosecutor is that my client read that one email and closely reviewed the attached Excel spreadsheet that contained the “misleading revenue numbers”? Never mind that my client works in marketing, not finance, and has no clue what should or shouldn’t be in a 10K and no clue what revenue numbers were correct. Well, surely, he must have known that the CFO engaged in fraud, right? And surely he must remember that email with the attachment with these numbers from five years ago, right?

(And if he sticks by his explanation that he doesn’t remember it, then he’s trying to be “difficult” or is trying to “avoid answering questions.”)

Again, it makes no sense.

No Sense of Humor

Beyond the forgetting curve, prosecutors have one third quirk: they have no sense of humor. Really. Jokes in emails consistently fall flat in a proffer. Even if my client’s habit is to send darkly humorous responses or goofy puns or questionable “locker room” jokes in emails, that’s of no moment in a proffer. Words are interpreted literally, and a joke is twisted into criminal intent.


Emails are key evidence in pretty much any white-collar case. That makes sense. What doesn’t make sense is a prosecutor assuming that my client is lying because he doesn’t remember a single email shown to him in a stressful proffer session five years after the fact.


  1. Itys simple. they are idiots, who cannot function outside of a seemingly limitless budgeted agency. They are angry that they got picked on in High School and or jealous that they cant make the kind of money that your client does. You don’t go work for the Government, beyond say 2 years, or God forbid make a career of it, unless you cannot be a real lawyer, in the free world. Too much time in Mommies basement playing video games.

  2. Excellent point, great stats! REALLY sad about the humor, though — but then, everyone has different gifts …

  3. What I find more amusing is when they try to pressure an interview despite having exculpatory e-mails that literally direct actions exactly aligned with the law. They’re out to prove guilt however they can find it, not the truth.

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