It takes a long time to cut someone's head off. Heads are not being chopped off in this war. They are being cut off, with knives. When Falah Aziz does it, the person is lying on their back with him standing over them, sawing their head off with a knife.
He sometimes has to pull the knife out again and have another go, to get the head to come off. To get a steady grip, he holds onto the chin of his victim with his other hand.
Iraqi police officers are standing around as he cuts people's heads off. Someone else films it.
When a young man's head has been cut off, Falah Aziz cries:
"The knife has done its work!"
His colleagues shout excitedly that "Falah Aziz is cutting ISIS's head off."
Suffocating them with their hands
On his Facebook page, he is holding up a bloody knife in his profile picture. Other videos show him walking around, with Iraqi troops, carrying a severed head. And beating blindfolded men who are sitting on the floor, with their hands tied behind their backs and hoods over their heads.
The prisoners are being beaten with things like batons, and one of them is being suffocated by someone's hands over his mouth.
You do not see whether anyone dies, but Falah Aziz says:
"Every day, I swear, I slaughter them, as they've slaughtered us."
In a video showing torture, men's voices bark orders at each other:
"Get the pillow."
A prisoner with a shaved head protests:
"You accuse me!"
"It's the law!" replies the man who is beating him.
"You accuse me, seriously," the prisoner complains.
Wears a designer jacket
Falah Aziz looks like just another Iraqi police officer or soldier. He walks around in military boots and wears the same brand of jacket worn by a lot of the troops, a black 5.11.
But he stresses that not everyone fighting ISIS does what he does:
"No, no. Not everyone."
He is talking about his own actions. He says that beheading is his speciality. None of the people he is fighting alongside can be seen protesting when Falah Aziz cuts people's heads off. On the contrary. They celebrate when he's chopped a head off.
Videos of the executions
Several of the videos in Falah Aziz's mobile phone clearly show his colleagues within the Iraqi Police Force, and Iraqi Armed Forces, not simply watching on in silence as he tortures prisoners and cuts their throats.
In one video, you can see a large group of soldiers parading down the street screaming, with Aziz leading the way and holding a severed head in one hand.
Another video shows a close up of Aziz cutting the head off a young man or boy, while surrounded by Iraqi troops.
In yet another video - which Aziz shared with us to demonstrate what he has done, but the image quality is too poor to determine whether he is involved - Iraqi troops can be seen beating men wearing civilian clothes and with their hands tied behind their backs, lying on the floor of a building.
The beatings are extremely brutal and radiate immense rage. The men on the floor are being beaten with whips, something that looks like power cords and a metal object on a chain. The men being beaten cannot protect themselves, they just scream.
"I slaughter them"
The photos and videos Falah Aziz has in his mobile phone and the material he has published on his Facebook page have changed over the years and changed with the war. He shows off the videos as if they were normal.
His voice is indifferent and resolute:
"My specific wish is that I slaughter them."
He has kept count of the people he has killed:
"50 that I've cut the heads off. But 130 in total," he claims. Adding that "so far" he has "slaughtered" 50.
When asked whether the people whose heads he has cut off were dead or alive, he says:
"No, no, alive."
And when specifically asked whether what appears to be a young man or boy being beheaded was alive or dead, Falah Aziz says:
"He's alive, him. We grabbed him in the toilets."
Public toilets have become a common hiding place during the war on ISIS. It is usually the last place troops check, which is exactly why people have started hiding in them.
No justice or fair trial
Falah Aziz finds it easy to describe why he is doing this to the people who are captured:
"They've driven us to it. What they've done has killed our compassion. Finding your brother slaughtered, or your mother slaughtered. What are you going to do? You don't know what you're going to do. What they have done to us, we must do to them."
Refers to Shiite leader
By "them" he means ISIS. But the prisoners being tortured and killed are not getting a fair trial. Falah Aziz feels good about taking their lives.
"Just that feeling, I can't explain how at ease I am with it," he says about what it feels like to behead someone.
Falah Aziz has been fighting against ISIS since the first battle in Mosul when ISIS stormed the metropolis in the summer of 2014.
"Mosul fell, the battle relocated to the Bagdad Belts and to Kurdistan."
He describes how he has moved along the fronts. Now he is fighting with the Iraqi Federal Police Force's 5th Division and refers to his commanding officers as "heroes Ali Alami and Abou Dergham".
He explains that Iraq's most senior Shiite cleric, Grand Ayatolla Ali al-Sistani, called upon the people to fight against ISIS.
Ali al-Sistani issued a fatwa in which he urged the Iraqi people to declare jihad on ISIS, which resulted in 100,000 people joining the war – both civilians and people with paramilitary backgrounds from the many militias that existed in Iraq.
The majority of the Iraqi population are Shia Arab Muslims. Under Saddam Hussein, Sunni Arabs were in power, but after the US invasion in 2003, all of Saddam Hussein's security forces, as well as his Ba'ath Party, were dismantled. Since then, the governments have been Shia dominated.
al-Qaeda established itself
In 2006-2007, there was a civil war in Iraq between Sunni and Shia groups, a war that began in the power vacuum after the US invasion, when a group of Sunni Arabs formed a resistance movement and Sunni extremists, al-Qaeda, established themselves in the country.
The Sunni uprising and al-Qaeda in Iraq were targeting Shia Arabs and Westerners. Even Shia forces turned on the Western troops after the invasion. Falah Aziz feels that, among others, the Shia forces have done a lot for the war on ISIS – that they have been avenged and, by slaughtering ISIS, brought honour back to Iraq.
Now he is fighting in areas that are still under ISIS control in West Mosul. A few weeks ago, he was shot in the thigh by an ISIS sniper.
Describes ISIS as Sunni Arabs
He describes ISIS as mostly Sunni, a mix of Saddamites and terrorists, who joined forces and took control of Sunni areas in Iraq in order to proclaim a separatist state for Sunni Arabs.
It is an opinion he shares with a lot of Iraqi civilians as well as Iraqi generals – that ISIS is made up of former military from the Iraqi security forces dismantled by the US when Saddam Hussein was overthrown in 2003, of former al-Qaida in Iraq and of local mafia. Several of the people who joined ISIS have spent time in prison, among them the US-run Abu Ghraib prison in Iraq, which became notorious for torture and sexual humiliation.
Even ISIS's highest leader, Abu Bakr al-Baghdadi, spent time in Abu Ghraib before the US released him in 2010. ISIS illustrate the fact that Americans have been torturing Iraqis, by dressing their prisoners in the same orange overalls that the Americans have used in their prisons in Iraq and Guantánamo.
According to Falah Aziz, entire countries were involved in the emergence of ISIS:
"It's an Israeli plan, that they'd begun working together, Saddamites and terrorists." The goal, he believes, it to destroy Iraq. "Destruction. It's an Israeli and American plan."
A lot of oil fields have burned
The fact that the US invaded Iraq in 2003, after having invaded Afghanistan in 2001, is usually explained by people who share Falah Aziz's views as revenge for the 9/11 attacks. In other words, the goal was not to protect the Iraqi people, but rather to overthrow Arab-Nationalist Saddam Hussein, who was considered a threat to the US and Israel, and seize control of the oil.
A lot of oil fields have burned throughout the war. An oil well burns to the south of Mosul, as I stand talking to Falah Aziz.
He suspects that a local company has set it alight in order to then receive the contract to extinguish it. He mumbles about corruption and money. He feels that this kind of behaviour is not right.
"This is your blood"
Another of the videos in Falah Aziz's mobile phone shows him together with his colleagues from the Iraqi forces.
He is holding a knife. Both it and his hand are red.
"Here's the man who's slaughtering ISIS," cries one of the soldiers beside him.
Falah Aziz looks into the camera:
"This is your blood, you dogs."
Falah Aziz says:
"I swear, every Muslim is worth a thousand of you."
A young man in the background praises him:
Shows photos of his brothers
But in amongst his war photos are pictures that do not contain any violence. Four men feature regularly in his photos.
Their names are Ahmad Aziz, Ghazwan Aziz, Bashar Aziz and Waed Aziz. They are his brothers. Were his brothers. Older brothers.
"Now they're martyrs," he says.
"One of them was a teacher. What did he ever do to get slaughtered? He has five children."
Falah Aziz finds it harder to talk:
"Four of my brothers died in my arms. I'm the youngest. My brother said, 'Don't leave me.' I can't explain."
But he knows that it made him want to do the same thing in return:
"As they slaughtered my brothers, I slaughter them."
"I expect to die"
His mouth has responded to every single question in a clear and straightforward manner, but his eyes have said nothing. They express nothing.
The philosopher Friedrich Nietzsche once warned, "He who fights monsters should take care lest he becomes a monster himself. For if you gaze into the abyss long enough, the abyss will also gaze into you."
Falah Aziz sees nothing but the abyss. He has climbed into it. And he has no plans to leave it.
The war has become part of him. Part of his skin, his thoughts, his soul. He does not even think he will go on living.
An attitude he shares with many of the ISIS members he has fought against.
"I expect to die, not to remain here."
Translator: Laura Åkerblom