Are there bad people?

I am curious about this question, as I am usually an extremely forgiving person. I usually am not able to hate anybody, on the news, when we see a murderer- or a pedophile, or an abuser- my parents always say "Wow, what a disgusting person.", or, "We really need the death penalty back."- but I've never understood this.

Please do not take this as me trying to act like a saint; because I am anything but one- but I have learned that I am overly forgiving. I even talked with my therapist about it, because sometimes I can feel bad for feeling sorry for 'bad' people.

So, is there such thing as a clinically 'bad' person? I mean, I personally have been so mired in my own pain, or anxiety, or trauma, that I act selfish; or mean. So why could this not be the case for these 'immoral' monsters? They are human too, no? They have thoughts, feelings, parents, and needs; like all of us. And how do we know they are bad? They may just be confused, sad people, lost in a confusing, sad, world.