Locally-slaughtered meat in a country with a mixed population of Muslims, Christians and idol-worshippers
Question

                We live in a country with a mixed population of Christians, idol-worshippers and ignorant Muslims, and we do not know whether they mention the name of Allaah when slaughtering the meat or not. What is the ruling on eating meat slaughtered by all of these people, when it is difficult to distinguish what has been slaughtered by whom?.
Praise be to Allah.If the matter is as 
    described, with the meat being slaughtered by a mixture of people that 
    includes people of the Book, idol-worshippers and ignorant Muslims, and you 
    cannot tell who has slaughtered what and it is not known whether the name of 
    Allaah was mentioned at the time of slaughter or not, then it is haraam to 
    eat the meat when you are confused about who did the slaughtering, because 
    the basic principle is that animals of the an’aam class (i.e., camels, 
    cattle, sheep and goats), and animals that come under the same rulings, are 
    haraam unless they are slaughtered in the proper manner as prescribed in 
    sharee’ah. In this case there is doubt as to whether the slaughtering is 
    done in the proper shar’i manner or not, because of the mixture of 
    slaughterers, some of whose meat is permissible and some is not permissible 
    – such as the idol-worshippers and innovators among the ignorant Muslims 
    whose bid’ah involves shirk. 
If it can be determined 
    what has been slaughtered by whom, then you can eat meat slaughtered by a 
    Muslim or a Christian if it is known that he mentioned the name of Allaah at 
    the time of slaughter, or if it is not known whether he mentioned the name 
    of Allaah or not. But you may not eat meat slaughtered by an idol-worshipper 
    or by a Muslim who follows innovation that involves shirk, whether he 
    mentioned the name of Allaah over it or not. 
The Muslim should strive 
    to be on the safe side in all matters of religion and he should seek that 
    which is halaal in his food, drink, clothing and all his affairs. With 
    regard to matters such as that asked about here, the Ahl al-Sunnah should 
    choose the right people to slaughter their meat.