Behavior can be good or bad. But people themselves aren't good or bad-they have the capacity for doing either. As Aleksandr Solzhenitsyn wrote in The Gulag Archipelago, “The line separating good and evil passes right through every human heart, and through all human hearts.”
Evil is not a thing you can point at and say, “There it goes!” or “Here it is!” Evil is a privation. A negation. Not something in itself. It's like rot to a tree. Without the tree, the rot wouldn't exist. Without a context of good, evil doesn't exist. So if you want to declare something evil, then you must also come to terms with what is good.