“Earth Skills” is episode two of season one of The 100.
In the first episode, “Pilot”, some of the hundred (or at least those that actually made it to the ground alive) on the ground discovered that they were not alone when Jasper was hit, and apparently killed, with a spear. Although it seems that he may not actually be dead. Others were taking off the wristbands that monitor their vital signs and transmitted them to the Ark so that it appeared that they were dead, which would mean that no-one else will follow.
Things are starting to get seriously out of control, and the Ark is really starting to fall apart, and if they don’t have a solution soon, people will be culled.
Just noticed that this is based on a book. Guess it wasn’t made into a film, like so many others.