A former classmate of Luigi Mangione said he “almost had a heart attack” after finding out the 26-year-old was arrested Monday on suspicion of killing UnitedHealthcare CEO Brian Thompson. “He would be the last one I would think would do something like this,” Freddie Leatherbury, who attended the Gilman School—an all-boys private institution in Baltimore—with Mangione told The Baltimore Sun shortly after his arrest. “He was a nice kid.” Police in Altoona, Pennsylvania took Mangione into custody M