A police-known Islamist allegedly carried out a deadly attack during Berlin’s Pride event, raising serious security concerns.

The suspect, identified as 21-year-old Abdul B., reportedly drove a van into a crowd at the Christopher Street Day event, resulting in one death and 29 injuries. Authorities are now facing scrutiny over how a known extremist was able to commit such an act.

Abdul B. had been under police observation for years due to his Islamist affiliations, having been known to authorities since he was 16. He was recently released from a youth sentence for preparing a terrorist act and was required to participate in a deradicalization program, which had not yet been finalized.