The former head of a Michigan medical marijuana licensing board has agreed to plead guilty to accepting $110,000 in bribes to influence his decisions when he led the panel over a two-year period, authorities said Thursday. Charges against Rick Johnson and three other men were announced by U.S. Attorney Mark Totten at a press conference in the capital, Lansing. Johnson was chairman of the marijuana board for two years until spring 2019. The Republican also was one of the most powerful lawmakers in the Capitol, serving as House speaker from 2001-04.