All night long, Jewish volunteers stood solemnly in the rain outside the Tree of Life synagogue, where 11 dead bodies lay inside, sealed off with yellow crime-scene tape. The deceased were not supposed to be left alone, according to Jewish tradition, from the moment of death until burial. So when the medical examiner removed the bodies at 5 a.m. Sunday, the volunteers were there to escort them to the morgue.

Earlier in the night, the volunteers had been allowed to peer briefly inside. They saw a scene of carnage, with bodies sprawled everywhere. Once homicide investigators give them the all clear, they intend to meticulously clean the crime scene. They consider everything left behind to be sacred remains, to be preserved and buried with the bodies.

Judaism has a strict set of laws governing death: Burials are expected to take place as soon as possible, autopsies are discouraged, and bodies are ritually washed and clothed in white shrouds. But balancing observance with a complex criminal investigation is presenting a rare set of challenges for the mourning families and religious leaders. Never before in modern American history have there been so many people murdered in one Jewish community.

“This is what we do — the community needs us and we mobilize — but we have never seen anything like this before,” said Rabbi Daniel Wasserman, who runs the Orthodox burial society in Pittsburgh, known as a chevra kadisha. “These are people who were killed because they were Jewish, they are bodies of holy martyrs.”