While capture by Israel is likely to be easily confirmed, establishing that a Hamas leader is (a) deceased (b) as a result of an action taken by the state of Israel, I will consult assessments and statements given by (1) Hamas, (2) IDF/Israel (3) intelligence services of other states such as the US, France, UK, etc.; as well as reporting by established media outlets such as the New York Times, Wall Street Journal, CNN, BBC, etc.
Related questions
Ismail Haniyeh? See list below
“Al Jazeera’s team on the ground said the dead from the Haniyeh family included Zahr Abdel Salam Haniyeh, Nahed Haniyeh Abu Ghazi, Iman Haniyeh Umm Ghazi, Ismail Nahed Haniyeh, Muhammad Nahed Haniyeh, Moamen Nahed Haniyeh, Zahra Nahed Haniyeh, Amal Nahed Haniyeh, Shahad Nahed Haniyeh and Sumaya Nahed Haniyeh.
“