One Palestinian inmate died with a ruptured spleen and broken ribs after being beaten by Israeli prison guards.Another met an excruciating end because a chronic condition went untreated. A third screamed for help for hours before dying.

The details of the prisoners’ deaths were recounted by eyewitnesses and corroborated by doctors from Physicians for Human Rights Israel (PHRI), who sat in on autopsies, the findings of which were shared with families and obtained by The Washington Post. The three men are among at least 13 Palestinians from the West Bank and Israel to die in Israeli jails since October 7, according to PHRI. An unknown number of prisoners from the Gaza Strip have also died.

Rights groups say conditions in Israel’s jam-packed prisons have deteriorated dangerously since October 7. Former Palestinian prisoners described routine beatings, often carried out on entire cells or sections, usually with batons and sometimes with dogs. They said they were denied sufficient food and medical care and were subjected to psychological as well as physical abuse.

The Washington Post spoke to 11 former prisoners and half a dozen lawyers, examined court records and reviewed autopsy reports, revealing rampant, sometimes deadly violence and deprivation by Israeli prison authorities.

While international attention and condemnation has focused on the plight of Gazan detainees — specifically at the notorious Sde Teiman military site — rights advocates say there is a deeper, systemic crisis in Israel’s penal system.

“Violence is pervasive,” said Jessica Montell, executive director of the Israeli rights group HaMoked, which has worked for years with Palestinian inmates. “It’s very overcrowded. Every prisoner that we’ve met with has lost 30 pounds.”