“There is nothing inherently illegal about accepting money fromforeign interests if you are a private citizen and your dad is a famous, powerful person. But you do have to pay taxes on it. And according to the New York Times, a federal inquiry into whether Hunter had properly paid his taxes began back during the Obama administration. Then, in 2018, the tax inquiry became a broader federal criminal investigation into Hunter.”
…
“In 2018, during a period in which Hunter has admitted to having a serious drug addiction (he wrote a book about it), he bought a gun. In connection with that purchase, he filled out a federal form and attested that he was not a drug user. The gun became an issue when his sister-in-law became concerned he might harm himself and threw it in an outdoor trash can, where it was discovered and reported to police. Texts from his laptop make clear he was not particularly stable at the time, but no one was hurt.”
https://www.vox.com/politics/2023/5/12/23715711/hunter-biden-investigation-taxes-indictment