In accordance with Jewish custom most of the victims were buried immediately, before autopsies could be performed. According to a two month investigation by the NYT:
"Investigators with Israel’s top national police unit, Lahav 433, have been steadily gathering evidence but they have not put a number on how many women were raped, saying that most are dead — and buried — and that they will never know. No survivors have spoken publicly.""The Israeli police have acknowledged that, during the shock and confusion of Oct. 7, the deadliest day in Israeli history, they were not focused on collecting semen samples from women’s bodies, requesting autopsies or closely examining crime scenes. At that moment, the authorities said, they were intent on repelling Hamas and identifying the dead.""A combination of chaos, enormous grief and Jewish religious duties meant that many bodies were buried as quickly as possible. Most were never examined, and in some cases, like at the rave scene, where more than 360 people were slaughtered in a few hours, the bodies were hauled away by the truckload."
https://www.nytimes.com/2023/12/28/world/middleeast/oct-7-attacks-hamas-israel-sexual-violence.html
