ARLINGTON (WDVM) — The FBI released preliminary details on the fatal stabbing of Pentagon police officer George Gonzalez Tuesday morning.

Federal investigators say on Tuesday around 10:43 am, Austin William Lanz exited a bus at the Pentagon Transit Center in Arlington, VA, and with no provocation immediately attacked officer Gonzalez with a knife.

According to authorities, during a struggle between the two Lanz shot himself with the officer’s service weapon. Responding officers rushed over to Lanz, who ultimately died at the scene. A bystander was injured during this incident and transported to a neighboring hospital for non-life-threatening.

The motive behind this incident is still unknown. The FBI continues to investigate.