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.
There is a consensus of opinion among the jurists that animals slaughtered by the People of the Book are lawful. Allah 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]
Food means slaughtered cattle and edible animals. On the other hand, dead animals, which have been killed by strangulation, by a violent blow, by a head long fall, or by the goring of horns, are prohibited in the Quran.
Here are some rules:
1. If it is proved that the eatable animals are killed by strangulation, or by electric shock, or by sinking them, it becomes unlawful to eat them.
2. If it is proved that the animal is slaughtered according to legal ways; i.e., blood shedding, it is lawful, whether it is from a Muslim, a Jew, or a Christian.
3. You are not required to ask about the manner of slaughtering as long as you are in a Muslim country.
For more benefit, please refer to Fataawa 81380 and 81384.
For more benefit on meat of animals slaughtered by the People of the Book, please refer to Fataawa 82323, 82065, 81234, 393961, 330952, 82899, and 84072.
Allah knows best.