"Everyone deserves to have a robust defense". Allegedly. Even a murderer whose murder was witnessed by millions? WHY?

I got into quite a sturdy and hearty disagreement here with a long-time good friend. She sees it as you do. Honestly I don't know what's wrong with me but I think according someone like a Derek Chauvin who COMMITTED MURDER in plain sight of many witnesses and to this day apparently has shown no remorse nor even pretended to. His entire demeanor was arrogant and IN YOUR FACE as he glared at those taping him and for over 9 minutes didn't move his knee from the neck of the man he MURDERED. In fact minutes after the man had NO PULSE and was apparently DEAD he kept pressing that knee down. People implored him to STOP. His three buddies just stood there and watched him commit murder and did nothing to stop him. Why should he be defended? As i said there is something either wrong with me or wrong with the system. Further if he gets 40 years how many millions of dollars will we have spent feeding housing clothing and medical treatmenting him? A homo sap like that? See what I mean? Clearly something is very wrong with me. I haven't spoken yet with anyone who feels and thinks as I do about this. BAD ROSIE? Maybe but it is how I feel and what I think. Thank you for your reply! :)