Straw buyer

[INSIDIOUS]

Supreme Court rules against 'straw buyer' in gun case | Reuters The part of this that is not clear to me is when you can't sell a gun legally?

The Supreme Court handed a victory to gun control advocates on Monday by upholding the conviction of a former police officer from Virginia who lied when he stated he was buying a handgun for himself when it actually was for a relative. In a 5-4 ruling focused on the role of what is known as a "straw buyer" for a gun, the court upheld Bruce Abramski's conviction for making a false statement when he bought the gun. He had filled out a form, required under federal law, saying he was the prospective owner, when the gun was intended for his uncle. The court was split along ideological lines, with the liberal wing in the majority with swing vote Justice Anthony Kennedy. The dissenting justices, from the conservative bloc of the court, said the federal law in question makes no distinction between people who purchased guns for themselves and buyers who intend to pass the gun on to others.

In this case he admits to buying it for his uncle, is that SOLE technicality that caught him? Any reason he couldn't have purchased a gun, then next day decide to sell it to a private party?