A working group led by Vice President Biden is seriously considering measures backed by key law enforcement leaders that would require universal background checks for firearm buyers, track the movement and sale of weapons through a national database, strengthen mental health checks, and stiffen penalties for carrying guns near schools or giving them to minors, the sources said.

To sell such changes, the White House is developing strategies to work around the National Rifle Association that one source said could include rallying support from Wal-Mart and other gun retailers for measures that would benefit their businesses.