CHROMOSOME 21 on Netflix is a new Spanish-language crime thriller series from Chile (org. title: Cromosoma 21). The title of the series comes from a murder suspect with Down syndrome. Can he stand trial? Or even be a killer?! Read our Chromosome 21 series review here!

CHROMOSOME 21 is a new Netflix series from Chile (org. title: Cromosoma 21). In other words, it’s a Spanish language production and the genre is crime-thriller. The series begins when the police are called out to a scene where someone has been murdered.

There they find a young man with Down syndrome. He is the only one there and has blood on him, so they arrest him and bring him in. People with Down syndrome have an extra Chromosome 21, which is where the title comes from.

Continue reading our Chromosome 21 series review below. There are eight 45-minute episodes in the series which is on Netflix (in select countries including the US) from February 8, 2023.

A very different premise for a murder investigation

When the series begins, the young man with Down syndrome, Tomás (Sebastián Solorza), is found at the scene of the crime and has blood on him. He also grabs onto a metal rod, when the police approach him and ask him to put his hands up. Don’t worry, the actual arrest is very peaceful once they realize that he has Down syndrome. Also, he is completely compliant.

However, getting him to talk is more difficult. Not because he can’t but whether it’s PTSD or something else keeping him from explaining what happened, is the first of many questions that need to be answered.

The judge is clearly uncomfortable and wants to hear from the suspect, Tomás (or Tommy, as he goes by). Early on, the lead homicide detective,  Mariana Enríquez (Valentina Muhr) goes to a theater group called “Down UP” where all the actors have Down syndrome.

There the teacher, Sofía (Claudia Di Girólamo) is quick to remind her that people with Down syndrome have unique personalities. Just like anyone else.

Once she starts talking to the other actors in the troupe, she hears both good and bad about Tommy. As you would expect when asking about anyone. But nothing that screams “murderer” or points towards any kind of guilt.

Chromosome 21 – Review | Netflix Crime Series

Can someone with Down syndrome commit murder?

The main plot of Chromosome 21 is tied into the fact that it’s the first time a person with Down syndrome is a murder suspect in Chile. This immediately leads to core questions such as; Is a person with Down syndrome capable of murder? And can he even stand trial if the evidence points toward his guilt?

As already stated by the theater teacher, everyone (whether they have Down syndrome or not) is a unique individual with their own ideas and passions. Sure, Tomás could be capable of murder, but first, the evidence needs to point in that direction.

And then there’s his brother who goes by “Beckham”. He has been the one to care for Tomás (or Tommy) for a long time, as their parents died long ago, but isn’t necessarily the best influence on an impressionable young man.

Watch Chromosome 21 on Netflix now!

The 8 episodes in the series are directed by Matías Venables who also took part in writing the series with Emilia Noguera,
Vladirmir Rivera, and Pablo Toro.

To me, Chromosome 21 is an intriguing murder mystery with a premise that managed to point the spotlight on many issues. Especially how we act and react to someone who is different from the norm.

Are eight episodes too much for such a story? Well, yes, I think so. I suspect many viewers will find it drags on and has too many irrelevant subplots. And it does. But that doesn’t take away from the core murder mystery. Even if you’ll likely guess most “twists” way before they’re revealed.

Maybe even during episode 1. And that’s not good for a crime or thriller series that has this many episodes.

If they removed some of the subplots and focused more on the main story, it could’ve been a tight mini-series in four episodes. I think more people would watch it then and that would be a good thing.

All eight episodes of Chromosome 21 is on Netflix from February 8, 2023.


Cast: Mario Horton, Valentina Mühr, Sebastián Solorza, Gastón Salgado, Claudia Di Girólamo, Pía Urrutia, Daniel Muñoz, Alejandro Trejo, Amparo Noguera, Sergio Hernández


When the police discover a man with Down syndrome hiding at a crime scene, they launch an investigation to determine whether he’s a witness or a suspect.

I write reviews and recaps on Heaven of Horror. And yes, it does happen that I find myself screaming, when watching a good horror movie. I love psychological horror, survival horror and kick-ass women. Also, I have a huge soft spot for a good horror-comedy. Oh yeah, and I absolutely HATE when animals are harmed in movies, so I will immediately think less of any movie, where animals are harmed for entertainment (even if the animals are just really good actors). Fortunately, horror doesn't use this nearly as much as comedy. And people assume horror lovers are the messed up ones. Go figure!
Karina "ScreamQueen" Adelgaard
Latest posts by Karina "ScreamQueen" Adelgaard (see all)