[Assad troops]Reuters In July 2014, a Syrian government defector, code-named Caesar, provided international investigators with startling evidence of abuses within the Assad regime's prison system. Caesar reported that more than 10,000 people had died in government custody since the 2011 outbreak of the Syrian Civil War and provided photos documenting what The Wall Street Journal described as "evidence of [an] industrial-scale campaign." Caesar asserted that a horrifying atrocity was unfolding in Syria outside of the public's view, and that the regime of Syrian President Bashar al-Assad was doing a disturbingly effective job of covering its tracks. Without a single, anonymous regime defector, the scope and systematization of Assad's abuses would have remained concealed. And even with Caesar's information, Assad's detention facilities remained one of Syria's dark zones, with little subsequent information about a policy that even 18 months ago had already been responsible for tens of thousands of deaths. A UN Human Rights Council report released on February 3 sheds much-needed light on Assad's prisons. The report, entitled "Out of Sight, Out of Mind: Deaths in Detention in the Syrian Arab Republic," is the result of a thorough investigation of the detention practices of the Assad regime, as well as antigovernment groups including ISIS and the Al Qaeda affiliated Jabhat al-Nusra. [Syria map February 2016]Reuters The section on regime abuses rests on extensive evidence. Human Rights Council investigators conducted 621 interviews. It talked to over 500 survivors of detention centers, and held over 200 interviews with "former detainees present at the deaths of cellmates." Investigators obtained government documents related to Assad's detention program, and spoke with people who had worked in the regime's prison facilities — as well as with the families of detainees who had died in custody. A harrowing picture emerges from the report's findings. The Assad regime maintained a squalid prison system where torture and summary executions were deliberate policies — and tried to hide its crimes from the Syrian people and the international community. Here are the report's major findings: [An image of Syria's President Bashar al-Assad is seen on a car parked in front of damaged buildings in the town of Rabiya, after pro-government forces recaptured the rebel-held town in coastal Latakia province, Syria January 27, 2016. REUTERS/Omar Sanadiki ]Reuters WIDESPREAD TORTURE "Former detainees detailed how cellmates were killed as they were beaten to death during interrogations and in their cells, or died as a result of severe injuries sustained due to torture or ill treatment," the report states. The report includes the story of an elderly detainee who died after being hanged by the wrists for over three hours, and multiple accounts of detainees who died from suffering bodily mutilation under torture and being denied any subsequent medical treatment. The torture wasn't limited to a single prison, or to just a handful of problematic military units. Instead, it appears to be systematic and the result of general regime policies. The report lists a number of detention facilities in the Damascus area in which detainees died as the result of torture — facilities that were overseen by a number of different branches of the regime's security services, including Military Security and Air Force Intelligence. Of the 500 former detainees investigators interviewed, some 200 of them had been "present at the death of their cellmates," while "almost all" of them "described having been the victims of and witnesses to torture and inhuman and degrading treatment." [ALEPPO RUBBLE]REUTERS 'INHUMAN' PRISON CONDITIONS Dozens of prisoners would be packed into tiny holding cells, where they would be fed infrequently, forced to drink wastewater, and subjected to frequent physical depredation. "In some detention facilities," investigators report, "guards threw cold water on the floor of cells, forcing detainees to sustain long periods of cold temperatures, further weakening their resilience to illnesses." Detainees were denied medical care, something that turned treatable illnesses into a protracted death sentence. "A high number of prisoners across detention facilities died of severe and continuing diarrhea, likely caused by the unhygienic conditions and the inadequate standard of food in the prisons," the report states. "The victims would often suffer for months before death occurred." The report includes jarring anecdotal evidence of the high death rate within individual detention facilities. An Assad regime prison is a hard place to survive: "A former prisoner recounted how, in a cell holding 60 detainees in [Military Security] Branch 227 [in Damascus], six died in the course of a week in January 2013. "In the same detention facility, between January and March 2014, in a cell holding 12 men, three prisoners died as a result of deteriorating health and lack of medicine, or as a consequence of torture. Between March and October 2013, in [Military Security] Branch 235 [in Damascus], around 20 detainees were observed to have passed away in a cell holding 100 prisoners." The victims weren't just males of fighting age or even alleged militants. Investigators found evidence that the regime essentially kidnapped civilians to terrorize the population into accepting Assad's rule: "The commission has documented cases of women and children as young as seven years old dying in the custody of State forces." [Syrian President Bashar al-Assad speaks during a meeting with Russian President Vladimir Putin at the Kremlin in Moscow, Russia, October 20, 2015. REUTERS/Alexei Druzhinin/RIA Novosti/Kremlin ]Reuters THE COVER-UP Investigators didn't just uncover systematic detention and torture. The Assad regime also made a concerted effort to ensure that the world would never find out about abuses committed at detention facilities. When a detainee died, the family would be issued a death certificate from the Tishreen military hospital in Damascus, showing that that family member had died of a heart attack — the report includes the story of a single family where three male relatives had died of "heart attacks." Families wouldn't be informed of a detainee's place of detention or death. Bodies would almost never be released back to families, although investigators found instances of families being able to recover bodies after signing a statement acknowledging that "terrorists" had been responsible for that family member's death. The report also contains evidence that the regime tried to cover up the mass killing of detainees. In one specific case, regime forces tried to dispose of the bodies of scores of executed detainees. The report states: "In Aleppo city, bodies started appearing in Queiq River in January 2013, reportedly after having been dumped in the Government-controlled area of the city. "Some of the victims were confirmed to have been detained by State forces, including the Air Force Intelligence Branch in Aleppo. Many of the more than 140 victims had their hands tied behind their backs and appeared to have been executed by gunshot." [Aleppoiswmap]Reuters The report helps confirm some of the most serious human-rights accusations leveled against the Assad regime. But as International Institute for Strategic Studies senior fellow Emile Hokayem noted in a February 5 article for Foreign Policy, the Assad regime has successfully shifted the terms of what the international community considered acceptable within the context of the country's civil war, winning increased freedom of action for itself with each successive atrocity. "Assad all along pursued a strategy of gradual escalation and desensitization that, sadly, worked well," Hokayem writes. The Assad regime has committed numerous human-rights atrocities in Syria, ranging from chemical warfare to the starvation of entire towns. And Assad has seen his world position improve as international actors shift their attention to the fight against ISIS and Syria's non-jihadist rebels lose ground. In December, the US indicated that it didn't believe a Syrian peace process needed to be conditioned on Assad's ouster. Assad's forces have now nearly encircled Aleppo, one of the last redoubts of the country's non-jihadist rebels, thanks to an infusion of Iran-backed militia forces and increased Russian airstrikes. The Human Rights Council report captures Assad's brutal tactics in prosecuting his country's civil war. His probable battlefield victory in Aleppo, and increasing stature, show that these atrocities are paying off. READ THE FULL UN REPORT HERE. NOW WATCH: An AT&T spokesperson and former refugee is now helping Syrian refugees in Greece