He does not know whether the animal was slaughtered in the prescribed manner or died as a result of stunning
Question

The Germans slaughter animals, and they are instructed to stun the animal before slaughtering it. What is the ruling on this meat, when they are regarded as being People of the Book?
Praise be to Allah.Firstly:
The basic principle is that what is slaughtered by one of the People of the book is halaal, whether he is a Jew or a Christian, because Allah, may He be exalted, says (interpretation of the meaning): {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} [al-Maa’idah 5:5].
Secondly:
In order for meat slaughtered by a Muslim or one of the People of the Book to be halaal, it is stipulated that it be slaughtered by cutting it in the right place, cutting the two veins in the neck. If in addition to that, the trachea, which is the airway, and the oesophagus, through which food and drink reach the stomach, are also cut, that is better. As for stunning the animal before slaughtering it, that is subject to further discussion.
If the slaughtering is done when the animal is still alive, it is permissible to eat it, such as if the stunning is light and the slaughterman hastens to slaughter it straight away.
But if the slaughtering is done after the animal has died, it is not permissible to eat it, and it comes under the heading of mawqoodhah [that which is killed by a violent blow], which refers to an animal that is shot or struck with a stone or stick until it dies without being slaughtered in the prescribed manner, as was narrated from Ibn ‘Abbaas, al-Hasan, Qataadah, ad-Dahhaak and as-Suddi. Tafseer al-Qurtubi (6/46).
This is indicated by the verse in which Allah, may He be exalted, says (interpretation of the meaning) {Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah , and [those animals] killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and those from which a wild animal has eaten, except what you [are able to] slaughter [before its death]} [al-Maa’idah 5:3].
The words { except what you [are able to] slaughter [before its death]} are an exception which indicates that that which is killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and that from which a wild animal has eaten, are halaal if they are reached when they are still alive and are slaughtered in the prescribed manner.
What is meant by still being alive here is that it is not on the brink of death and could survive for a while, which may be known from the animal’s movements during slaughter, and the gushing of blood from it.
Ibn Qudaamah (may Allah have mercy on him) said in al-Mughni (9/322): That which is killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and that from which a wild animal has eaten, and that which is affected by disease and dies of it, are all haraam, unless they can be slaughtered in the prescribed manner before they die, because Allah, may He be exalted, says: {except what you [are able to] slaughter [before its death]}. According to the hadith of the slave woman of Ka‘b, it says that one of her sheep was injured, and she reached it [before it died] and slaughtered it with a stone. Ka‘b asked the Prophet (blessings and peace of Allah be upon him) about it, and he said: “Eat it.” If there had been nothing left of life in it except something like the movement of an animal when it is slaughtered, it would not become permissible even by slaughtering it in the prescribed manner.
But if a person reaches it when it is still alive and could survive for a while, and he is able to slaughter it, it is permissible, because of the general meaning of the verse and report quoted above. It is all the same whether it had reached a state in which it was known that it could not survive or that it might survive, because of the general meaning of the verse and the report, and because the Prophet (blessings and peace of Allah be upon him) did not ask or seek the details of the matter. Ibn ‘Abbaas said concerning a case in which a wolf attacked a sheep and gravely wounded it, and its trachea fell to the ground, and he reached it before it died and slaughtered it with a stone: Throw away whatever fell on the ground, and eat the rest of it.
Ahmad said regarding one animal that gravely injured another, until it was looked as if it was about to die, but there was still some life in it – meaning that it was then slaughtered: If it shook its tail or blinked its eye, and the blood flowed [when it was slaughtered], then I hope – if Allah wills – that there is nothing wrong with eating it. That was narrated with its isnad from ‘Uqayl ibn ‘Umayr and Taawoos, who said: It moved; but they did not say: Its blood flowed. This is according to the madhhab of Abu Haneefah. Ismaa‘eel ibn Sa‘eed said: I asked Ahmad about a sick sheep which they feared would die, so they slaughtered it, and nothing more is known about it except that it blinked its eye or moved its front leg or back leg or tail weakly, and its blood flowed [when it was slaughtered]. He said: There is nothing wrong with it. End quote.
The Permanent Committee for Ifta’ was asked: What is the ruling on eating the meat of animals slaughtered in a Muslim country by means of stunning? Please note that the animal is subjected to stunning until it falls to the ground, then the butcher slaughters it as soon as it falls to the ground.
They replied: If the matter is as described, that the butcher slaughters the animal as soon as it falls to the ground after being stunned, if he is able to slaughter it when there is still life in it, it is permissible to eat it, but if he slaughtered it after it died, it is not permissible to eat it. That is because it comes under the ruling on mawqoodhah [that which is killed by a violent blow], and Allah has prohibited it unless it is slaughtered properly. Slaughter is not valid unless it is proven to have still been alive [at the time of slaughter] by the movement of a front or back leg or the flow of blood and the like, which indicates that it was still alive until process of slaughter was completed. Allah, may He be exalted, says (interpretation of the meaning):
{Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah, and [those animals] killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and those from which a wild animal has eaten, except what you [are able to] slaughter [before its death]} [al-Maa’idah 5:3].
Thus He has permitted animals which have been injured and are about to die, on condition that they are slaughtered in the prescribed manner, otherwise it is not permissible to eat them.  "Fataawa al-Lajnah ad-Daa’imah (22/455)"
It also says (22/456):
Firstly: if the animal is stunned by a blow to the head or an electric shock, for example, and it dies as a result of that before being slaughtered in the prescribed manner, it comes under the heading of mawqoodhah [that which is killed by a violent blow] and cannot be eaten, even if its neck is cut after that, because Allah, may He be exalted, forbade it when He said (interpretation of the meaning):
{Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah, and [those animals] killed by strangling or by a violent blow …} [al-Maa’idah 5:3]. And the scholars of Islam are unanimously agreed that such animals are prohibited.
But if the animal is reached when it is still alive, after being stunned, as described above and the like, and it is slaughtered properly, then it is permissible to eat it, because Allah, may He be exalted, says at the end of this verse which speaks of [those animals] killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and those from which a wild animal has eaten: {except what you [are able to] slaughter [before its death]} [al-Maa’idah 5:3].
Thus Allah, may He be glorified, made an exception from these prohibitions for that which is reached whilst it is still alive and slaughtered in the prescribed manner. Such meat may be eaten, because the slaughter is valid, unlike that which dies as a result of being stunned before slaughter. In the latter case, slaughtering it will not change it and make it halaal. Thus it is known that the Qur’an forbids animals if they die as a result of stunning before being slaughtered, because the one that dies as a result of stunning comes under the same heading as mawqoodhah [that which is killed by a violent blow], and Allah has stated in the verse in al-Maa’idah that it is haraam, unless it is reached whilst it is still alive and slaughtered in the prescribed manner.
Secondly:
It is haraam to stun an animal with a violent blow, electric shock and the like, because this is a kind of torture, and the Prophet (blessings and peace of Allah be upon him) forbade harming and torturing animals, and he enjoined gentleness and kindness in all things, and when slaughtering in particular. Muslim narrated from Ibn ‘Abbaas (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said: “Do not take anything that has a soul as a target.” And Muslim narrated that Jaabir ibn ‘Abdillah (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) forbade capturing any animal for the purpose of killing it (for sport). Muslim also narrated from Shaddaad ibn Aws, from the Prophet (blessings and peace of Allah be upon him) that he said: “Allah has prescribed proficiency in all things, so if you kill, kill well, and if you slaughter, slaughter well. Let one of you sharpen his blade and spare suffering to the animal he slaughters.”
If it is not possible to slaughter an animal except after stunning it to a degree that will not kill it before slaughtering it and the like, it is permissible to stun it, but it must be slaughtered whilst it is still alive.End quote.
Thirdly:
If the matter is as described, that they stun the animal before slaughtering it, then there are three possibilities:
1.. What we know was stunned then slaughtered before it died. This is permissible to eat.
2.. What we know died as a result of stunning. This is not permissible to eat.
3.. If it is not known what is the case, then we base it on what is most likely to be the case. If the prevalent practice in the country is that they slaughter the animal after it has died as a result of stunning, then it is not permissible to eat this meat of which its case is unknown. If the prevalent practice is that they slaughter it when it is still alive, then it is permissible to eat it.
And Allah knows best.