Specifically, going after people who lie on their background checks:
Nearly 80,000 Americans were denied guns in 2010, according to Justice Department data, because they lied or provided inaccurate information about their criminal histories on background-check forms. Yet only 44 of those people were charged with a crime.
In the face of those difficulties, the White House has said it is looking for actions it can take without Congressional approval. Increasing the number of prosecutions for lying on background-check forms is an effort that the administration can undertake largely on its own, in part by pressing federal prosecutors to pursue such cases. It is also one measure that both sides of the gun-control debate have agreed upon.