Omar was taken by his father at age 12 to fight against 'foreign' invaders to Afghanistan in the aftermath of 9/11. At age 15, Omar Khadr was part of a close combat where an American soldier was killed. This soldier was killed by a hand grenade that at first was allegedly thrown by a middle aged looking 'insurgent'. For some reason, that account got changed to match the 15 year old youth we know as Omar Khadr. He was the only survivor of the insurgent side.
He was quickly shipped off to Guantanamo Bay detention center in Cuba.