Mikhail Ivanobich Bystrov

Mr. Bystrov is a retired St. Petersburg police colonel who, according to the indictment, joined the company in February 2014 and became its highest-ranking official. He also led shell entities that were used to conceal its activities, including one called Glavset, a so-called database and information company. It shared an address — 55 Savushkina Street — with the Internet Research Agency. (The troll farm has since moved to Optikov Street, according to the local press.) The troll farm soon drew notice in Russia: news outlets reported that it employed 250 people in 12-hour shifts to provide a round-the-clock flow of pro-Kremlin posts and comments, praising Mr. Putin and excoriating President Barack Obama and President Petro O. Poroshenko of Ukraine. Monthly salaries ranged from $1,100 for a junior analyst to $1,400 for a blogger to $4,200 a month for senior management. Mr. Bystrov, who is believed to be 59, has avoided reporters and declined interview requests.