Parents of murdered children

I know it's not a happy fun topic. I was actually against the death penalty until my 16 year old talented smart and athletic child went to visit his dad in Florida . Appear entry some people knew emit hat inside his fathers house was possibly marijuana and cash. My son was only their for Thanksgiving, his dad was a chef he has subsequently passed away. They lived in a safe gated community two guys broke in one only 16 and they had a get away driver waiting outside. My son gave them every and anything of value. The super next door heard the commotion and came in he was also robbed so instead ohms jumping in their car and leaving the oldest said "ya know I wonder what it feels like to kill someone. So he killed my son and shot the super in the head. Luckily he lived being and eye witness maybe they could catch these guys! Well they did the killer is on death row in Florida and the other two are doing twenty and twenty three years. Due to their charges they don't qualify for parole . I was raised Roman Catholic I didn't believe we had the right to take a life. UNTIL this. Why do they get to live, how could they and why he was just a boy. I Won't rest until the killer is put to death. I am a person who values life at 45 I cry when my goldfish died. No abortions I avoid ants. Not this. This is different for me. And it hurts to want this I will even be there to witness it. I always say judge not lest ye be judged to me this is different And until you have walked a mile in my shoes please don't judge me I am going against everything I know and I can't stop myself. HELP