As the U.S. presidential race began roaring to life in 2016, authorities in the former Soviet republic of Latvia flagged a series of " suspicious" financial transactions to Hunter Biden and other colleagues at a Ukrainian natural gas company and sought Kiev's help investigating, according to documents and interviews. The Feb. 18, 2016 alert to Ukraine came from the Latvian prosecutorial agency responsible for investigating money laundering, and it specifically questioned whether Vice President Joe Biden's younger son and three other officials at Burisma Holdings were the potential beneficiaries of suspect funds. "The Office for Prevention of Laundering of Proceeds...