The entrance to the Regional Court in Düsseldorf, Germany, is seen in this file photo.
CNN  — 

A German court sentenced a member of a Western-backed Syrian armed opposition group on Monday to life imprisonment for “war crimes,” according to court documents.

The convict, identified as Ibrahim A., was found guilty of “torture and killing persons protected under international humanitarian law” as well as “murder, extortionist kidnapping and the commission of war crimes under the International Criminal Code.”

The 43-year-old commanded a 150-member armed group known as Ghoraba as-Sham which operated under the Free Syrian Army (FSA) umbrella group, according to court documents.

Over the course of Syria’s nearly eight-year war, Western nations have aided and trained members of the FSA, who have been considered “moderate opposition” amid a rebel landscape that has become increasingly dominated by extremists such as ISIS and al Qaeda.

The FSA, which began as a group of Syrian soldiers and officers who defected from the Syrian army, is an association of over a dozen rebel groups fighting the Russian-backed government of Syrian President Bashar al-Assad. The group has taken over whole neighborhoods, and sometimes cities and provinces, during the war. Many FSA-held territories have been recaptured by Syrian government troops over the years.

Ibrahim’s militia controlled neighborhoods in northeastern Aleppo where they allegedly took part in “plundering and abducting and captivating people … and torturing and militating members of his militia,” according to the Upper District Court in Düsseldorf.

“In one case, a kidnapped victim who had been tortured in a prison of the accused died as a result of severe torture and physical abuse,” the court document read. Ibrahim A. denied the allegations.

Allegations of torture and arbitrary detentions are rampant on both sides of Syria’s war. International rights groups have repeatedly documented widespread physical abuse and mass executions in Syrian government prisons since the start of the war in 2011.

The Syrian Network for Human Rights reports that as many as 81,000 people have been forcibly disappeared after arrests by the Syrian regime.

On Monday, the Higher Regional Court of Frankfurt sentenced a German citizen and former ISIS member, identified as Abdelkarim E.B., to 10 years in prison.

The 32-year-old was found guilty of “criminal aid to a war crime against persons” and “membership in a terrorist organization in a foreign country.”

The Frankfurt-born man joined ISIS when he traveled to Syria in 2013. The case against him was built on an ISIS torture incident that he filmed. The court said it considered Abdelkarim “criminal aid to a war crime.”