Connecticut School Shooting: History of U.S. gun control laws (VIDEO)

(CBS) -- "CBS This Morning" reports on America's past gun laws and the changes some are calling for after the Friday shooting at Sandy Hook Elementary School in Newtown, Conn. that left 27 dead.

Pictures: Conn. elementary school shootingPictures:  Mass shootings in 2012

New York Mayor Michael Bloomberg, a staunch gun control advocate, is taking the President to task on the issue. "... The country needs [the President] to send a bill to Congress to fix this problem. Calling for 'meaningful action' is not enough. We need immediate action," Bloomberg said yesterday after the shooting.

The last significant national gun control legislation, the assault weapons ban, expired in 2004.

Complete coverage of the Sandy Hook Elementary School massacre