Professor McKnight shows that the group of criminals who were the core of the habitual criminal group in Song China were young unattached males with few life skills.

• 包括杀人犯、抢劫犯、流氓犯罪团伙分子、教唆犯、在劳改劳教中继续传授犯罪技术的惯犯，以及人贩子、老鸨儿等。