On April 12, 1980, a military coup led by Master Sergeant Samuel Doe of the Krahn ethnic group overthrew and killed President William R. Tolbert, Jr.. Doe and the other plotters later executed a majority of Tolbert's cabinet and other Americo-Liberian government officials and True Whig Party members. The coup leaders formed the People's Redemption Council (PRC) to govern the country. A strategic Cold War ally of the West, Doe received significant financial backing from the United States while critics condemned the PRC for corruption and political repression.
Who led a military coup that killed the American ambassador?
{'text': 'Master Sergeant Samuel Doe', 'answer_start': 42}