It's those "Laws on the Books" preventing Sensible Gun Regulation.

“We need to enforce the laws already on the books.”

You've heard that before right? Even though there are many more common sense regulations that could be passed, we should not do anything until we start enforcing existing law. Many of those laws are of course, after the fact, but what the heck.

But what about those laws already on the books that prevent us from stopping the carnage?

Here’s a list of federal laws that stun the senses and stop reform, from ProPublica:

1. A federal firearms trace database is off-limits to the public:  How often do federally licensed gun dealers sell guns that are then used in crimes? It's hard to know, because for nearly a decade such gun trace data has been hidden from the public. Since 2003, the Tiahrt Amendments, so named after the former Kansas Republican congressman who introduced the measures, have concealed the database from the public. Prior to 2010, local police could access the database only to investigate an individual crime but not to look for signs of broader criminal activity (Thankfully, Obama changed that in 2010). (Still) the ATF can't require gun dealers to conduct an inventory to account for lost or stolen guns; records of customer background checks must be destroyed within 24 hours if they are clean enough to allow the sale; and trace data can't be used in state civil lawsuits or in an effort to suspend or revoke a gun dealer's license.

2. The military can't impose additional regulations on service members who own guns: Following the November 2009 shooting at Fort Hood military base in Texas that killed 13 people and wounded more than two dozen others, the Department of Defense proposed guidelines that included a new policy around private firearms. (The semiautomatic pistol used by accused gunman Army psychiatrist Maj. Nidal Malik Hasan was purchased at a store off-base.) Less than a year after the shooting, U.S. Sen. Jim Inhofe, R-Okla., introduced a bill prohibiting new regulations on Defense Department personnel's private guns. It also prohibited commanders from inquiring into private gun ownership (this part was recently repealed). At the time, Inhofe stated that the measure would "prevent current and potential Second Amendment violations for those serving and employed by the Department of Defense."

3. The gun industry is shielded from many lawsuits involving criminal misuse of guns: In 2005, Congress enacted a law that immunizes gun dealers and manufacturers from liability for injuries resulting in the "criminal or unlawful misuse" of a firearm. The law authorized dismissal of any applicable pending lawsuits and prohibited future claims (though lawsuits are still possible, many more are likely dismissed because of this law).

But here’s my favorite. This is why we haven’t seen innovation and a safer gun design:

4. Congress has removed federal funding for firearms-related research: Funding used to be set aside for the Centers for Disease Control and Prevention to research the impact of gun ownership — but that was taken away in the mid-90s. The NY Times explains that as the CDC became "increasingly assertive about the importance of studying gun-related injuries and deaths as a public health phenomenon," the NRA assailed its findings as politically skewed and lobbied to defund research. One study commissioned by the CDC found that the risks of keeping a gun in the home outweigh the benefits. In 1996, an amendment proposed by then-Arkansas Republican Congressman Jay Dickey removed $2.6 million from the center's budget, the same amount earmarked for firearms research. When funding to CDC was later restored, legislation included the directive that "none of the funds made available for injury prevention and control at the Centers for Disease Control and Prevention may be used to advocate or promote gun control."