Hunter Biden was indicted Thursday on federal firearms charges, the latest and weightiest step yet in a long-running investigation into the president’s son.

Biden is accused of lying about his drug use when he bought a firearm in October 2018, a period when he has acknowledged struggling with addiction to crack cocaine, according to the indictment filed in federal court in Delaware.

President Joe Biden's son has also been under investigation for his business dealings. The special counsel overseeing the case has indicated that charges of failure to pay taxes on time could be filed in Washington or in California, where he lives.