A 36-year-old man from Minnesota was arrested Wednesday evening after allegedly attempting to free high-profile defendant Luigi Mangione from federal custody in Brooklyn by impersonating an FBI agent. Federal authorities identified the suspect as Mark Anderson, a resident of Mankato, Minnesota. He was expected to make his initial appearance in Brooklyn federal court on Thursday. The defense has challenged aspects of evidence and is fighting against the possibility of prosecutors seeking the death penalty in federal court. Jury selection in the federal case is scheduled for September, while New York state prosecutors are pushing to begin the state trial as early as July.