2. He's really a law-down dirty shame.
他真是个不知羞耻的家伙。

law-down dirty shame“不知羞耻的”
 
*不知羞耻还可以用shameless,to know no shame,faceless等来表达。但如果是要表达出有点蔑视的味道，a law-down dirty shame更合适。

如： I wouldn't like to have anything to do with a law-down dirty shame like her.
我可不想和她那样不知羞耻的人有任何来往。