def face_detected_bool(d):
    """
    Support function for rekognition_json_to_df()
    Return boolean test of whether one or more Face detections were recorded
    in an AWS Rekognition response.
    d -- python dictionary resulting from json.load(json_source_file)"""
    bool = set()
    for idx in range(len(d['Persons'])):
        person = d['Persons'][idx]['Person'].keys()
        bool.add('Face' in person)
    return True in bool