I Suspect ...

 ... that the sinful amongst us are all capable of repentance and that the 'evil' are not. As this is not spelled out as such in Scripture, I must take this more as a 'rule of thumb' than as a 'spiritual absolute'. We must allow at all times for God's sovereignty, however.

I note that:

Nazi concentration camp  guard John Demjanjuk has died at the age of 91.

Ukrainian-born Demjanjuk was a guard at Sobibor camp in Nazi-occupied Poland and helped in the extermination of 28,000 people.
No further observations.