Can a Tiger Change Its Stripes?

Does it matter where you've been in life? Can a tiger change its stripes? Can people change?

These questions have been filtering through my mind lately. I hold that I don't really care where you've been, I care where you are going. But, if you've been to the dark side, and you've been there repeatedly, can you change and go on a different path?

Can you trust someone that has a history of being untrustworthy? Can you, by including them in a circle so completely different from where they've been, help change their stars.

Or, are they forever doomed?