U.S. President Joe Biden’s son Hunter was indicted on federal charges that he purchased a firearm without disclosing that he was unlawfully using drugs, thrusting his legal problems further into the spotlight as the president ramps up his re-election campaign.

The charges Thursday by Special Counsel David Weiss follow the collapse of a deal under which Hunter Biden agreed to plead guilty to two misdemeanor tax crimes and to acknowledge a firearms violation without a conviction. But the deal, which involved no jail time, imploded in July when a federal judge questioned its terms and refused to sign off on it.

The gun charges represent the least of Biden’s legal jeopardy, as Weiss has signaled he is considering bringing charges for the president’s son’s alleged failure to report millions of dollars in income, including from China and Ukraine. A person familiar with the matter said the investigation into Biden is ongoing and additional charges are possible. House Republicans have also launched an impeachment inquiry of Joe Biden based on suspicions that the president somehow benefited from his son’s overseas business activities.