All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The basic ruling regarding the slaughtered animals of the People of the Book - the Jews and the Christians - is that they are lawful (halal), as Allah the Almighty says (what means): {This day [all] good foods have been made lawful, and the food of those who were given the Scripture is lawful for you and your food is lawful for them.} [Quran 5:5]. However, if the People of the Book did something that necessitates its prohibition when slaughtering it, then it is not permissible for a Muslim to eat from the slaughtered animal. There are two things that necessitate the prohibition from eating from their slaughtered animal:
First: If the animal was slaughtered in other than the name of Allah, such as slaughtering in the name of Christ or his mother, then it is forbidden as Allah the Almighty says (what means): {Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah.} [Quran 5:3] The view that meat slaughtered in this case is forbidden is the opinion that we adopt here at Islamweb, as it is the view of a group of the Companions. Ash-Shawkani, may Allaah have mercy upon him, said in Fat'h Al-Qadeer:
"'Ali 'Aaishah
and Ibn 'Umar
said: “If you hear a non-Muslim from among the People of the Book dedicating to other than Allah, then do not eat.” It is the opinion of Tawoos and Al-Hassan, and they stick to Allah the Almighty's saying: {And do not eat of that upon which the name of Allah has not been mentioned, for indeed, it is grave disobedience.}[Quran6:121] It is also indicated in the verse, {and that which has been dedicated to other than Allah.}[Quran 5:3]. Malik
said: “It is disliked and not forbidden." However, this disagreement is when we know that the People of the Book mentioned a name other than Allah's name when slaughtering their animals. But if we don't know whether they mentioned Allah's name or not, then At-Tabari and Ibn Katheer
reported that there is a unanimous agreement on its permissibility based on this verse.”
Second: To slaughter the animal by shooting or electrocuting it - as most Christians do today in Europe - and not slaughtering it according to Sharee'ah. If they applied this way in slaughtering the animal until it dies, then it will be considered as being killed by a violent blow and it is not permissible to eat it. If there is a doubt about whether the animal was slaughtered according to Sharee'ah or not, it can't be eaten either, because the basic principle in meats is prohibition, nothing of it is permissible except when they certainly have been slaughtered according to Sharee'ah which makes it permissible. Therefore, it is questionable whether the slaughter was done according to the Sharee’ah in this meat, so it remains forbidden because it is well known from their habit or the habit of most of them, as we mentioned, slaughtering by suffocation, shooting the head with bullets, or electrocution.
Allah knows best.