Alexanda Kotey was part of terror group cell of four Britons known for its extreme brutality
John Jihadi
Teenager attributed early display of remorselessness to threats she faced from extremists in al-Hawl
Furore over home secretary's failure to seek assurances pair would not be executed
Alexanda Kotey and El Shafee Elsheikh detained by Syrian Kurdish fighters
Muhiddin Mire (30), attacked 56-year-old musician Lyle Zimmerman with rusty knife
British citizen Mohammed Emwazi gained notoriety for filmed execution of hostages
Video appears to show the killing of five men who Isis claims were spying for Britain
Turkey is focused on detecting Islamic State fighters crossing its border