Michael Cohen agreed to cooperate with Special Advocate Robert Mueller's investigation into President Trump's relationship with Russia in the 2016 election. The agreement between Trump's former repairman and Mueller was revealed Thursday after Cohen pleaded guilty to lying to Congress about his talks on building a Trump tower in Moscow. Cohen confessed to Mueller that he had talked about the tower during the 2016 campaign and that he had repeatedly informed Trump and his family members. Cohen reportedly spent more than 70 hours at the special council office. Cohen's first hearing with the bureau took place on Aug. 7, according to court documents, two weeks before pleading guilty to violating Trump's election law to silence Stormy Daniels and Karen McDougal.