Every human has at least one redeeming feature. For example, Hitler was a vegetarian and he loved his dog. Of course he was responsible for the death of untold millions.
In my first novel, The Shadow Warriors, one of the bad guys sacrificed himself to save a woman from an explosion. I hadn't planned it, but it seemed right for the story.
In Chased by Death, the enforcer for the cartel, El Tigre, who was so scary it was hard to write about him. Then he broke down in tears because he needed the stolen money to pay for his wife's cancer treatment. Again, nothing planned. He was also nice to the children who were his hostages and played gamed with them. But he was still a killer.
In Murder in the North Woods, Darrell, a no-goodnik and murder victim, left a life insurance policy for his young son and showered him with presents using some of his blackmail money.
The biggest character redemption is in my just-published novel, Such Stuff As Dreams was the character of Snakes. Now anyone with the name, Snakes, is bound to be a little scary. Snakes appears to be a typical roue. Carla, the heroine, wants nothing to do with him, especially after she is told he tried to molest a thirteen-year-old girl. But then, she finds out the girl is lying, and she runs into Snakes at a cafeteria and shudders when he joins her. But his conversation is knowledgeable and interesting. Later he tells her his story and drives her and a friend to Mexicali on an errand of mercy. Snakes, despite his nickname and reputation, is a good guy.