The idea remains though - albeit not through the Church - by the Right of Asylum.
Article 14 of the 1948 Universal Declaration of Human Rights:
"Everyone has the right to seek and to enjoy in other countries asylum from persecution".
and in the 1951 United Nations Convention relating to the Status of Refugees and its 1967 Protocol
which prohibits the return of people persecuted on grounds of race, religion, nationality or membership of a particular social group or political opinion.
I'm not sure the mafia would pay much attention to any asylum really though, unless it meant putting you in one.