def determine_execution(execution_choices, roles):
    """
    >>> determine_execution([1, 0, 0], [1, 0, 0])
    True
    >>> determine_execution([0,0,0], [1, 0, 0])
    False
    >>> determine_execution([1,1,1], [1, 0, 0])
    None
    """
    agent_win = None
    bad = roles.index(1)
    # If bad chose themselves they win
    if execution_choices[bad] == bad:
        agent_win = False
    # If x num chose bad, good win
    elif sum(vote == bad for vote in execution_choices) >= (len(execution_choices) - 1) // 2:
        agent_win = True
    return agent_win