Federal prosecutors have officially charged Ryan Routh with attempting to assassinate former President Donald Trump, a source familiar with the matter confirmed to ABC News.

The move was expected and previewed both by prosecutors in a court hearing on Monday and by Attorney General Merrick Garland in a news conference Tuesday afternoon.

The charging documents have not yet been officially updated on Routh’s court docket. He is expected to be arraigned on the charges in a court hearing next week.

Routh, 58, had previously been charged with possession of a firearm as a convicted felon and possession of a firearm with an obliterated serial number for the incident that took place at Trump International Golf Club on Sept. 15.

This is a developing story. Please check back for updates.