An author I follow posted this on his Facebook account semi-recently, mostly joking about how impossible it is to use facts to make someone change their mind about ANYTHING, big or small.
It made me realize (and then Lulu_Key 's board reminded me of it) that the death penalty was something I changed my mind on when faced with additional facts. I used to be pro-death penalty, but have never been pro-torture, and then learned that, the conflicting rules of various systems basically require death row inmates to be tortured to death. You compound that with how targeted the American justice system is -- where the color of your skin or the size of your bank account can directly impact how "guilty" you are -- and the fact that there are known instances of police pushing innocent men to be found guilty and I just can't be in favor of it anymore. Maybe in a perfectly just society, as a way to weed out the most heinous, but not in any version of our current society.
Here's an interesting video if you want to learn more:
What's your thing?