For Abdelrahman al-Azy the task was brutal but the justifications were simple. As a member of ISIS, he must follow the instructions of his local emir or commander. The order: to help kill a man in cold blood.
As directed, al-Azy drove a fellow ISIS militant to the home of a SWAT member, an elite unit of the Iraqi Counter-Terrorism Service.
The 23-year-old sat in the car as his co-conspirator stepped out of the vehicle, then shot and killed their victim.
At the time, al-Azy says he felt proud of the murder, but now sitting in handcuffs, he told CNN he regrets his actions and believes they were wrong.
Al-Azy is one of three men who spoke to CNN exclusively from inside a Kurdish-run prison at an undisclosed location in northern Iraq.
A secret detention facility in northern Iraq where the three former ISIS members are being kept.
This is unprecedented access to a group of men who all admit they played a role in an ISIS attack on the Iraqi city of Kirkuk in October.
The commando-style raid involved a couple of hundred ISIS fighters, at least two suicide bombers, and local sleeper cells. It left 96 people dead and was considered by many a distraction from the battle to recapture Mosul, ISIS's stronghold in Iraq.
Each of the three men CNN spoke to played very different roles and held varying degrees of closeness to the terror organization. Together, their stories draw a picture of how the organization functions on a local-level at a time when it is fighting for its very survival.
All three of the men say they agreed to speak to CNN and were not coerced by the Kurdish officials that run the detention center. Each remains under investigation for their crimes.
Laith Ahmed was working as a carpenter when ISIS took control of his village near the predominantly Sunni city of Hawija in the summer of 2014. Three days later, a man came to him promising a salary if he joined the so-called Islamic State. Poor and illiterate, Ahmed says he agreed to sign-up without understanding the consequences of his decision.
"I made a mistake. I don't know how to read or write. Everything I did was wrong." Ahmed said as he fidgeted with his hands.
He is 26-years-old with shoulder-length, stringy blond hair and a long beard. His eyes are a striking blue-green and he has dark, pattern scars on his forehead and nose. In so many ways he is the ideal ISIS foot soldier: submissive in demeanor, uneducated, and from a hotbed of Sunni radicalism.
ISIS Fighter Laith Ahmed, who helped storm Kirkuk on October 21.
"I swear they tricked us. I don't know anything." Ahmed said, "The brought us on foot into Kirkuk and gave us AKs. Then they positioned us in specific locations and left."
Kurdish authorities tell us the 26-year-old was an inghamisi, meaning suicide fighter, and lead a group of five other men into the assault on Kirkuk. Ahmed tells us he is unaware of his position as an inghamisi.
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CCTV footage obtained by CNN shows Ahmed engaged in a brief gun battle before he is shot in the foot and forced to crawl to safety. Later a group of furious local residents capture and restrain him until Kurdish security forces take him into custody
"I hope this will be over soon. I don't know what my fate may be," Ahmed said, "But I will go to court and one day I hope I can be re-united with my wife and children."
Twenty-year-old Akram Ahmed was working in his cell phone repair shop when a man he knew to be a member of ISIS approached him for a job. Ahmed admits he was enamored with the idea of a nation ruled by the laws of Islam.
"The Caliphate persuaded us with religion. I am a student of sharia law in university. So these ideas are convincing to me," Ahmed explained.
The college student was asked to do reconnaissance and surveillance ahead of the Kirkuk attack. He used his mobile phone to film key government and security buildings and find weak points that ISIS militants could exploit to enter the city.
Twenty-year-old ISIS Reconnaissance Akram Ahmed who grew up in Kirkuk.
Many of the sites Ahmed photographed were indeed attacked by ISIS last month when Kurdish authorities say militants very nearly conquered the city.
"Everything that happened I bear responsibility for. Everything that happened is my fault," Ahmed said as his lips quivered with emotion, "I always think about it. I used to have friends in the Iraqi Security Forces."
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Ahmed says at the time he had very little understanding of the horrors of life under ISIS and felt distant from the beheadings, enslavement, and torture the group has immortalized in propaganda videos. Now he says he deeply regrets the actions he knows will follow him for the rest of his life.
"I hope there will still be a place for me in my community one day. Now if I walk in my street people will say I killed their children. If I go to the mosque people will say he killed my children. If I come to get married, people will say he killed our children." Ahmed said.
The money man
A year ago al-Azy pledged allegiance to ISIS's self-proclaimed caliph Abu Bakr al-Baghdadi over his mobile phone. As a resident of the Kurdish city of Kirkuk, he joined a sleeper cell and became responsible for distributing cash salaries to militants and their families.
Al-Azy said he worked for a year under ISIS before he was detained. He said he joined the extremists out of pure conviction and still considers himself a strict Muslim.
"I was a believer. I believed in the caliphate and I believed in the Islamic State." al-Azy said from prison, "They said the pledge to the caliph is from the days of the prophet and those who don't pledge are not Muslims. I was convinced by this."
After pledging allegiance to ISIS a year ago Abdelrahman al-Azy says he was used by a sleeper cell in Kirkuk to make cash deliveries to fighters and their families.
When CNN asked him what he believed should be done to non-Muslims, al-Azy said "if I'm speaking in the past, we believe in Islam that non-believers should be killed."
But now he says he was misled and wants nothing more to do with the organization he had killed for without question.
"I don't believe in the caliphate anymore. I am of course a Muslim and I still do my prayers. Nothing else has changed in terms of the practice of my faith. But regarding the Islamic State, I don't want anything to do with them." al-Azy said.
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The stories of these three men prove ISIS remains a resilient force, with deep -- often hidden -- support, capable of lashing out on multiple fronts even as Iraqi forces push deeper into Mosul. But while a US-led coalition of 62 nations threatens to degrade and destroy the group, al-Azy believes the self-proclaimed caliphate will survive.
"In Iraq they (ISIS) will survive because there are so many cells," al-Azy said, "Just look in Kirkuk. There were so many cells. In my opinion even if they lose Mosul they will exist in Iraq."