Some will say that people can change, others will say that people can’t change.
There’s an old saying stating that a leopard cannot change its spots.
People also perhaps can’t change who they intrinsically are. However, if you wait long enough people will show you who they really are.
A leopard remains a leopard, regardless of how it tries to cover its true self.
Some people are basically good, some are basically less good. It often just takes time to uncover a person’s real and true self.