By Penny Hoffmann

Abu al-Umarayn, the 2014 killer of prisoners such as Peter Edward Kassig, also known as Abdul-Rahman Kassig after converting to Islam has been killed via a U.S-led anti-ISIL Coalition airstrike in Syria on Sunday.

Humanitarian worker and ex U.S army ranger Kassig was taken in 2013 and was 26 at the time of his beheading in November 2014.

A Pentagon statment on Monday stated that “Coalition forces conducted precision strikes against a senior ISIS member, and killed Abu al Umarayn, and several other ISIS members on Dec. 2 in the Badiyah Desert, Syria.”

In a letter to his parents whilst in captivity, Kassig said “If I do die, I figure that at least you and I can seek refuge and comfort in knowing that I went out as a result of trying to alleviate suffering and helping those in need.”