The notorious Pol i Chakri prison lies just east of Kabul, Afghanistan.
For decades, and through different rulers, it was used to hold the most dangerous inmates or those that have committed the most serious crimes
One of its prisoners was once a man who fought alongside Nato troops, called them his comrades and walked on patrol beside them.
One night in August 2012, Sergeant Hekmatullah was shown a mobile phone video about a report where US soldiers allegedly desecrated the Quran.
He told ITV News that he flew into a mad rage, returned to the base which he shared with Australian servicemen and shot dead Private Robert Poate, Sapper James Martin and Lance Corporal Stjepan Milosevic.
Rosemary Day in Northern Ireland has lived through the same nightmare.
Her daughter Channing went to Afghanistan to teach first aid to Afghan soldiers - until one of them killed her and a colleague. She is one of at least 140 Nato troops- including 19 British soldiers - who've been killed in such insider attacks, known as "Green on Blue" deaths.
Given how elements in the Afghan security forces have attacked their own allies, Rosemary questions whether they can be relied upon to protect Afghans.
Now on death row, Hekmetullah is unrepentant: "I would do the same thing again," he told ITV News. "They have be rebuilding our country, but they should not insult our religion."