If someone murders or tries to kill a federal judge or public safety officer they should be faced with lengthy mandatory minimums and potentially the death penalty. Such a crime seeks to undermine the rule of law, and should be punished harshly.
It’s wrong for the government to impose the death penalty on a citizen under any circumstance, as the judicial system that would mete out the punishment is prone to errors and it’s impossible to bring back someone who was wrongly executed.