Because it's about sending a message. They've seen how popular this guy and his actions have become and are trying to throw everything at him so it puts off any copycats.
That would make him a martyr. I’m thinking the plan is to lock him up in max for life, then control the media narrative whenever his name comes up again.
The death penalty has not been executed in NY/federal court for decades right? Doesn’t seem like an actual threat. What they want to achieve is a good negotiating position for a plea bargain because they known a trial will be a shitshow.