Death penalty and stuff

Oh no... this topic again...
Anyway here is my opinion: in my point of view, death penalty shouldn't be used as a punishment system, because you're not punishing anyone with it. It's not justice, it's not punishment and most of all, it's not a way to solve a problem... it's just a cold act of revenge, degrading ourselves to the same level of the guilty person. I'm not against because of some kind of religious point of view (life is sacred and that kind of things), mostly because I'm not a religious guy. I'm against it because it's been proved that it doesn't work. Countries which use it (like the States) have not shown a decrease in their crime rates, so it's been proved that it doesn't solve anything. Besides, there's also the problem of making mistakes. Here in Chile (and I'm sure this happens in a lot of other countries as well), justice is not very efficient. There has been a lot of people who have been senteced to jail, only to find out later they are completly innocent. We cannot afford the risk of making mistakes with death penalty.
We all know the solution is not the death penalty. There's a lot of ways to solve this, like improving the education and the rehabilitation programs, but we just can't "kill our problems".