Let me give you an example of what @CottonWolf might be talking about.
A father has a daughter who is suffering from a crippling illness. She is in constant pain, is unable to physically or mentally function, and will never be cured. The father then reluctantly kills her, as quickly and painlessly as possible, and then turns himself in.
The jury then decides that given the circumstances, the father should get a reduced sentence. He isn’t let off the hook completely, but the sentence is nowhere near as long as that of a murderer.
I heard this story a few years ago, back when I was taking Law in high school. I might have forgotten a few details.
Now, whether the father was justified is definitely a matter for debate. I personally think he went too far, but understand why he did it. The jury ruled in his favor despite the judge’s wishes, but did not let him off the hook completely.
Cotton was NOT saying that it’s okay for someone to shoot a completely innocent man for no reason and get let off the hook. If the man who was shot brutally assaulted his loved one or did something awful to him personally, then the jury would take that into consideration when passing the sentence. If it was a perfectly innocent man who did no wrong, then they have no reason to be lenient towards the killer.
Anyways, both judges and juries have their pros and cons. That’s why it’s better to have them together, so they can balance each other out.