Iraqi authorities believe that the palace complex could contain the remains of hundreds of young soldiers slain by Islamic State militants last June. As many as 1,700 Shiite soldiers from nearby Camp Speicher were killed by the jihadists, a massacre seared into the national consciousness.

Since Iraqi government teams started the excavation earlier this month they have uncovered more than 160 bodies of young men, most of whom had been bound, shot, and then buried in mass graves.

For months, relatives have waited for news of their loved ones who went missing at Camp Speicher. Now the bodies exhumed in Tikrit, which are currently awaiting DNA testing at Baghdad’s central morgue, offer some of the first concrete evidence of one of the most grisly crimes committed by a group already known for its shocking brutality. Officials say identification cards found on several of the bodies bear names that match reported victims of Camp Speicher.