Does end justifies the means?

I agree that end doesn't always justify the means. if it's for self-related reasons, you can't rob to feed yourself, that would make social choas among all parts of selfsame nation, if someone was in war, he became a hostage with 5 others, and got a deal that if he kills 2 he can go free with the other three, but if he doesnt yhey all are going to die. now that's a better choice than staying a hostage or being killed with the other five.

some people say its still unethical to kill an innocent. that if you all die it's better because you were never the killer (that's from the crime and punishment story from dostoyvsky) that you will be crippled with regret,but it's still the more beneficial choice imo