Are people able to change?

There are those who argue that people can only change as a result of a significant emotional experience such as religious conversion, a brush with death or a major traumatic event. Is change always good? Do people have the capacity to change from good to evil or does the path lead in both directions? In the thriller, Sing me the Anger, Travis Kilborn was an upstanding individual. He was a tenured, award-winning teacher, husband, father and community volunteer. What were the conditions that led to his change and did he have a choice in the matter? In contrast, Justin Manus was a selfish and brooding narcissist on the verge of suicide. What conditions prompted him to redirect his life? How much is change related to simply being a personal choice or is it all about one's environment and social conditions?