Despite making more than 1,200 arrests of the rioters at the U.S. Capitol on Jan. 6, 2021, one mystery of that incident remains unsolved: the FBI has never caught the alleged bomber who planted pipe bombs outside the national headquarters of both the Republican and the Democratic parties the night before the riot. In fact, the FBI has been so perplexed by the supposed bombing attempt that earlier this month, CBS News noted the feds had jacked up the reward for an arrest to $500,000. “The unsolved mystery continues to elude investigators three years later, even amid a public campaign providing …