The default ruling on the slaughter of Muslims is that it is lawful

Question:
May Allah reward you with good and do you good. Regarding the same topic, may Allah reward you with good. Shaykh Salih asks: Is it permissible to eat the meat of the general Muslim population who slaughter in the markets? We do not know whether they pray, fast, or whether their religion or tawhid (the oneness of Allah) is complete. We also do not know if they are among those who travel long distances to graves, or if they perform the prayer or the pillars of Islam. We know nothing about them, but they are from the general Muslim population and their status is unknown. Is it permissible to eat their slaughtered meat? May Allah reward you with good. If you would be so kind as to help us with the evidence.

Answer:
The one who slaughters in the lands of Muslims, the default ruling is that it is lawful, until it is known that the slaughterer is not a Muslim and not from the People of the Book. If it is known that the slaughterer has no religion, neither Muslim nor from the People of the Book, then his slaughtered meat is not eaten. However, as long as it is not known, and this meat was slaughtered in the lands of Muslims, the default ruling is that it is lawful. The Prophet (peace and blessings be upon him) was asked about meat brought into the markets of Muslims, where it was not known whether the name of Allah had been mentioned over it or not. The Prophet (peace and blessings be upon him) said: "Eat, and mention the name of Allah." Thus, the Prophet (peace and blessings be upon him) permitted eating from the slaughtered meat brought into the lands of Muslims, because the default ruling is that it is lawful, unless it is known otherwise. And all praise is due to Allah.