By Sarah N. Lynch WASHINGTON (Reuters) - Federal prosecutors on Tuesday will ask a judge to detain former Proud Boys chairman Enrique Tarrio pending trial on a conspiracy charge for his alleged role in the Jan. 6, 2021 Capitol riots, saying they had "compelling evidence" of his guilt and fear he may try to flee or obstruct justice. In a 21-page court filing on Monday, the Justice Department said it had damning encrypted messages exchanged between Tarrio and other Proud Boys who were invited to participate in a new chapter Tarrio created in December 2020 called the "Ministry of Self...