Is a ‘faceless’ preacher behind the Berlin attack?

German authorities are looking into whether the suspect behind the recent Berlin attack on a Christmas market is linked to a Germany-based Iraqi preacher named Abu Walaa, dubbed the “preacher without a face.”

Ahmad Abdulaziz Abdullah A., commonly known as Abu Walaa, hands out advice on his social media pages and appears in videos with his back to the camera or wearing a black shroud. According to Deutsche Welle, he is suspected of being one of the top recruiters for ISIS in the country.

According to the site, authorities are unclear as to how the attack suspect Anis Amri, a Tunisian refugee who was killed in a shootout with Italian police on Friday, was radicalized but believe the 24-year-old had made contact with members of Germany’s Salafist scene.

Federal Criminal Police Chief Holger Münch did not specify how the two men might be linked, despite floating the preacher’s name this week.

Walaa, 32, moved to Germany from Iraq in 2000 and originally lived in North-Rhine Westphalia.

He preached at a mosque in the northwestern state of Lower Saxony and built up an online following by sharing his thoughts on a number of mundane topics, including how to maintain a good marriage.

Despite his seemingly humdrum topics, German authorities reportedly kept a close eye on the preacher as his mosque had become a hotspot for Salafism in the country. Twenty men were thought to have been radicalized at the mosque before they left to join ISIS in Syria and Iraq.

In November 2016, Walaa was arrested on suspicion of launching a network to recruit ISIS fighters from Germany. Following his arrest, the federal prosecutor’s office in Karlsruhe said he had “pledged allegiance to the so-called ‘Islamic State’ and appeared as a speaker at numerous Salafist events in the past.”

However, German broadcaster n-tv reported that a lack of evidence makes it difficult to prove some of the more serious charges against Walaa.

The German government has said that almost 800 people left Germany in 2015 to join extremist groups in Iraq and Syria but it is still unclear how many of these can be linked to preachers.