The Third Criminal Senate of Germany’s Federal Court of Justice on Monday made public its decision to reject a Free Syrian Army member’s appeal against his conviction for war crimes, attempted homicide, torture, and membership of the Islamic State of Iraq and Syria (ISIS).

The Stuttgart Higher Regional Court sentenced Fares A.B. to 12 years in prison on November 19, after finding that he partook in several battles against the Syrian regime in 2012 as part of a sub-unit of the Free Syrian Army. Specifically, he had taken a captured member of a militia supporting the Syrian government to his unit’s headquarters, and executed him while he was handcuffed. However, there is some evidence indicating that the man did not die from Fares’ shots, but rather from shots fired by other individuals.

According to the court, Fares joined ISIS in June 2014 and within a month of his joining the group, he and two other members allegedly captured and beat two youngsters for over 30 minutes in a school used as a prison. It is also alleged that he detained another person in the same school for violating the ISIS code of conduct and that he performed road-side checks and made other contributions to the group until he left Syria in October 2014.

As the Federal Court of Justice found no error in the law with respect to the lower court’s judgment, it is now final.