Bloomberg View: What we don't know about gun violence

The following editorial appears on Bloomberg View:

How do criminals get their guns? Are there observable patterns to gun crime? Who is at the greatest risk of injury, or causing injury to others, from firearm use? Which gun-safety practices are most effective at preventing accidental injury?

The answers to these and other basic questions remain difficult and obscure in part thanks to a senseless ban, on the books for a decade, that limits research on gun violence and denies researchers and even police and prosecutors access to federal gun data. The laws prohibit the public disclosure of a gun's sales history, make that data inadmissible in court, require the Justice Department to destroy background-check records within 24 hours and prohibit the Bureau of Alcohol, Tobacco, Firearms and Explosives from requiring gun dealers to check their inventories annually for theft.

A recent report from the Institute of Medicine, an independent, nonprofit research organization, details just how thoroughly Americans are in the dark. The report, commissioned by President Obama after the massacre of 26 students and educators in Newtown, Conn., underscores how little even serious scholars know about gun violence and shows how such ignorance jeopardizes public safety and health.

A better understanding of the "characteristics of firearm violence," the "risk and preventive factors" for gun-related injuries, and the "impact of gun-safety technology," the report says, would undoubtedly help save lives. By making reliable gun data scarce, the research ban has hamstrung police, prosecutors and public health officials in their response to an onslaught of 30,000 gun deaths a year.

Congressional opposition to gun data, which advances the anti-research agenda of the National Rifle Association, isn't merely a policy position. The lack of information has successfully restricted public debate itself. Healthy democracies do not resolve conflicts by stifling inconvenient evidence. Imagine banning doctors from studying cancer cells or requiring radiologists to destroy X-ray records within 24 hours.

These laws, known as the Tiahrt amendments after their co-author, former Republican Rep. Todd Tiahrt of Kansas, should be repealed in full. Given the influence of the NRA in this Congress, however, repeal will probably have to wait for the arrival of less easily cowed legislators. In the meantime, Congress should confront the gun lobby on the issue that most directly hurts public safety: the inadmissibility of gun-tracing data in court. Police can't stop criminals if prosecutors can't bring them to justice.

Incremental repeal has also worked in the past. The NRA acquiesced to sharing gun-tracing data between police and criminal prosecutors in 2008 and to police use outside of criminal investigations in 2010. Prosecutors' inability to use the evidence, though, neuters these expansions.

Obama's efforts to aid research via executive action are having some effect. One of his orders instructs the Centers for Disease Control and Prevention that a ban on spending "to advocate or promote gun control" is not a ban on research funding, as the CDC had long interpreted it. That opens the door to research — but academics still lack money and data.

Vice President Joe Biden, who is working with Majority Leader Harry Reid and Democratic Sen. Joe Manchin of West Virginia, says he hopes the Senate will revisit the issue of background-check legislation. Background checks can make gun purchases more difficult for criminals and the mentally ill, but there is also a desperate need for research to better understand gun violence and responses to it. Repeal of the Tiahrt amendments should be at the top of a sensible to-do list.