Federal prosecutors will seek an indictment of Hunter Biden for illegally possessing a gun as a drug user by Sept. 29, according to a new court filing on Wednesday.

Biden is expected to be charged with two felony counts related to his purchase of a gun in 2018. At the time, he has said he was regularly using crack cocaine.

Prosecutors said last month that they also intend to charge President Joe Biden’s son with tax crimes, either in California or Washington, D.C.

The charges stem from a long-running federal investigation into the younger Biden. This summer, he nearly reached a deal with prosecutors to resolve the investigation without going to trial. But after a judge questioned the deal at a dramatic hearing on July 26, the proposed plea deal collapsed.