Everyone in My Family Has Killed Someone Is Coming to TV With Penn Badgley as Ernest Cunningham

There are some books that seem almost made for television, and Benjamin Stevenson’s Everyone in My Family Has Killed Someone has always felt like one of them.

Now it is officially happening because Amazon MGM Studios has ordered a TV series based on Stevenson’s murder mystery, with You star Penn Badgley taking the lead role of Ernest Cunningham.

The series will stream on Prime Video, though there is no release date yet and Badgley is currently the only cast member announced.

It is very good timing too. Stevenson’s Ernest Cunningham mysteries have quietly become one of the most popular modern takes on the traditional murder mystery.

With their mix of Golden Age rules, locked-room style setups, and family secrets, they are genuinely packed with clues ripe to be solved.

And Penn Badgley as Ernest? That could be a very interesting match.

What is Everyone in My Family Has Killed Someone about?

First published in Australia in 2022, Everyone in My Family Has Killed Someone introduces Ernest Cunningham, a crime fiction expert who earns money writing books about how to write mystery novels.

Ern is also part of a family with a rather unusual shared history in that every member of the Cunningham family has actually killed someone.

Not necessarily murdered someone, it should be said. Some deaths were accidents, some involved rather more complicated circumstances, and some definitely need explaining.

The family gathers at a snowy mountain resort to welcome Ern’s brother Michael home from prison. Ernest is not exactly thrilled about attending, particularly since he was the person who helped send Michael there in the first place.

Then a body is found in the snow. A storm cuts everyone off, family tensions start getting worse, and Ern finds himself trying to work out whether one of his relatives has added another death to the Cunningham family record.

It is a setup that should feel very familiar to anyone who loves Agatha Christie. A limited group of suspects, an isolated setting, plenty of secrets, and a reader who has been invited to solve the case alongside the detective.

But Stevenson has a lot of fun with those rules. He breaks the fourth wall, letting Ern talk directly to us, commenting on mystery writing while also taking part in a mystery.

He tells us what clues matter, sometimes points out when something will become important later, and regularly reminds us that a fair-play mystery should give the reader everything needed to solve it.

The clever part is that knowing those rules does not necessarily make the solution any easier. I should know, because despite my best attempts to solve the whodunit in one of his later books, I fell woefully short of coming up with a solution!

Why have the Ernest Cunningham books become so popular?

The first book was not simply a one-off hit. Stevenson followed it with Everyone on This Train Is a Suspect, which puts Ern aboard a train filled with crime writers. Naturally, someone ends up dead.

Then came the shorter Christmas mystery Everyone This Christmas Has a Secret, followed by Everyone in This Bank Is a Thief, which moves Ern into a bank robbery where the hostages soon become murder suspects.

The good news for fans is that a fifth Ernest Cunningham book is now being written.

The series has found a large international audience too. Penguin says Stevenson’s books have sold more than 1.5 million copies worldwide and have been published across 29 territories.

The first book alone has more than 250,000 ratings on Goodreads, which gives you some idea of just how far Ern has traveled beyond his original Australian audience.

There is also something very easy to like about Stevenson’s mix of old and new. These are modern books, but they really capture the essence of traditional detective fiction.

They are funny without turning the murder into a joke, complicated without becoming hard work, and self-aware without constantly trying to show how clever they are.

Penn Badgley To Play Ernest Cunningham

Badgley is obviously best known in recent years for playing Joe Goldberg across five seasons of Netflix’s You, which makes this casting slightly amusing, though many of you will also know him from his time as Dan Humphrey on Gossip Girl.

After spending years playing a man who kills people while convincing himself there is always a perfectly reasonable explanation for it, he is now moving into a show where practically everyone around him has killed someone.

Ern Cunningham is a very different character, though. He is dry, smart, observant and occasionally a little too pleased with his knowledge of crime fiction.

Stevenson appears very happy with the choice, saying Badgley captures Ern’s cleverness, while showrunner David Hemingson singled out the character’s intensity and dry sense of humor when discussing the casting. Badgley will also serve as an executive producer on the series.

One Big Change For TV

One interesting detail has already appeared in the official description.

Where Stevenson’s original novel is Australian and uses a snowy Australian mountain resort as its closed setting, the Prime Video version will be set in Vermont.

The main setup remains intact: Ernest attends the family reunion, Michael returns from prison, a frozen body appears, and everyone becomes trapped by a snowstorm.

That could also mean Ernest becomes American too, because realistically, transporting the whole family from Australia would raise more questions than answers.

When Will It Be Released?

Given that the announcement was only just made, there is no confirmed Prime Video release date, and filming dates have not yet been scheduled.

As of August 27th, 2026, the TV series is still in pre-production, so we still have quite a while before it hits our screens.

The project does have some strong names behind it. David Hemingson, whose credits include The Holdovers, will serve as showrunner and executive producer. Stevenson himself is an executive producer, along with Badgley, while Fifth Season and Made Up Stories are producing the series.

Interestingly, this is not the first time the book has attracted television attention. Screen rights were originally sold to HBO soon after the novel appeared, so an adaptation has been talked about for several years. The Prime Video series order finally means Ernest Cunningham really is heading for the screen.

Most importantly, there are already several more Ernest Cunningham mysteries sitting on the shelf if the first season works!

And considering Penn Badgley’s recent television history, he should at least feel reasonably comfortable spending time with a family where everyone has killed someone.