Who is Prosecutor Rachevsky from The Case of Comrade Tulayev and what is their importance?

Prosecutor Rachevsky is the lead prosecutor in the Tulayev case. He pushes for results. Rachevsky looks unhealthy. He has a bulging forehead, gray bulbous chin, and a curving nose that is swollen at the base with dark, hairy nostrils. His skin is sanguine with blotchy areas of violet. He has large chestnut-brown eyes that look like opaque marbles. Rachevsky eventually goes mad under pressure and is relieved of his position as prosecutor and put in charge of tourism.