The AI providers offer their services to institutions doing those killing. They make money from it. Of course they share part of the guilt
The knife company offers their products to people doing the stabbing. They make money from it. Of course they share part of the guilt.
If the knife was deliberately marketed and sold specifically to someone who the company knew would use it to stab someone, then, yes, the knife company shares part of the guilt.
If you sell a device that provides “knife action decision making”, and it decides to use the knife against kids, I hope you go to jail yes