FORT LAUDERDALE, Fla. — Circuit Judge Elizabeth Scherer was assigned the case of a former Florida student who gunned down 17 people in 2018 despite never having overseen a death penalty trial or one with much publicity.Her assignment to the Nikolas Cruz case was made randomly by a computer program that didn’t consider experience or the fact that no U.S. mass shooting of this magnitude had ever made it to court. The random selection process is used throughout much of Florida, but not by some other states.Jury …