Am I right in the belief that beef bone extract is not halal until it is known that the animal was slaughtered in a halal manner?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
It is not a prerequisite that the bones of an animal are from a halal slaughtered animal. In the Hanafi school, it does not matter if the animal is slaughtered in a halal manner or not to consider the bones halal, bones are always pure. But if the animal is impure, like pigs, the bones are also considered impure.
Only Allah knows best
Written by Maulana Selim Saldiran
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 al-Hidaya, Dar Ihya Turath al-Arabi, 3/46