Fol­low­ing med­ical res­i­den­cy, Dr. Mal­nak served as chief inter­nal med­i­cine, Army Hos­pi­tal, Fort Sill, OK, and a clin­i­cal inves­ti­ga­tor in liv­er dis­ease and med­ical direc­tor of the emer­gency depart­ment at Chicago’s Mount Sinai Hos­pi­tal. A board-cer­ti­fied internist in the Chica­go area, he was an assis­tant clin­i­cal pro­fes­sor at Stritch School of Med­i­cine for 25 years. His inter­est in the Holo­caust was sparked by the fact that his father’s entire Lithuan­ian fam­i­ly was mur­dered by the Nazis.