Remus attended the Illinois College of Law (later merged with DePaul University College of Law) and was admitted to the Illinois Bar in 1904. Remus specialized in criminal defense, especially murder, and became quite famous, due in large part to the highly publicized William Cheney Ellis murder case in 1914. It was in this case that Remus pioneered the "transitory insanity" defense that would evolve into what is now known as the "temporary insanity" defense. By 1920, Remus was earning $500,000 a year, approximately $ today.