I mean, confirmation there's any Hamas or military gear present would be a great start.
time.com
On Oct. 10, an air strike on the al-Najjar family home killed 24 people. On Oct. 22, an airstrike on the Abu Mu’eileq family home killed 19 people. Both strikes were in Deir al Balah. The city is south of Wadi Gaza, the area the Israeli military ordered civilians of Northern Gaza to flee to.
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Amnesty did not find any evidence of any military objectives at the sites of the strikes, nor any indication that the residents of the houses were affiliated with Hamas, leading the group to call for the air strikes to be investigated as possible war crimes

U.S. Munitions Traced to Possible War Crimes in Gaza: Report
Israel used U.S. military equipment to kill 43 civilians in Gaza—a possible war crime, Amnesty International says.