Could three seemingly simple laws really reduce US gun deaths by more than 90 percent?

Sentencing Law and Policy: Could three seemingly simple laws really reduce US gun deaths by more than 90 percent?
from CNN:

Passing federal laws that require universal background checks for firearm purchases, background checks on ammunition purchases and firearm identification could reduce the rate of U.S. gun deaths by more than 90%, according to a new study.  "We wanted to see which restrictive gun laws really work, as opposed to saying 'restrictive laws work,' and figure out if we are pushing for a law which might not work," said Bindu Kalesan, assistant professor of medicine at Boston University and lead author of the study...  in The Lancet.

Researchers arrived at the projection by looking at the number of gun-related deaths in every state in 2010 and the types of laws that existed in those states in 2009, including restrictive laws, such as background checks and child access prevention laws, and permissive laws, such as stand-your-ground laws.  They took into account differences in rates of gun ownership, unemployment and homicides that did not involve guns deaths.  Out of the 25 existing state laws that Kalesan and her colleagues studied, nine were associated with lower rates of gun-related deaths.

The researchers found the largest effects for universal background checks, which were associated with a 39% reduction in death, and ammunition background checks, which were associated with an 18% reduction in death. Laws around firearm identification, which make it possible to determine the gun that fired a bullet, were associated with a 16% reductions in deaths.

Researchers projected that federal laws expanding background checks for firearms purchases would reduce the U.S. gun death rate by 57%, while background checks for ammunition purchases would cut gun death rates by 81% and firearm identification would reduce the rate by 83%. The researchers said it would take many years to lower the rates so far.  Although a federal policy known as the Brady Law requires background checks on individuals who want to buy a firearm from a licensed dealer, it leaves a large gap, as an estimated 40% of firearms are acquired through unlicensed sellers, such as some online and at gun shows....

The researchers found that nine of the 25 laws they analyzed were linked to higher rates of gun-related deaths. Another seven laws did not seem to have an impact one way or the other on gun-related deaths.  Some of the laws that were linked with greater numbers of gun related deaths came as a surprise to the researchers. For example, bans on assault weapons, such as semi-automatic guns, were associated with a 15% increase in mortality....

In an editorial published with the study, Harvard School of Public Health Professor David Hemenway said the study was "a step in the right direction" to understand the scientific evidence about policies to reduce gun violence. But, he said, cutting mortality rates so dramatically is more complicated than simply implementing background checks for firearms and ammunition. "That result is too large -- if only firearm suicide and firearm homicide could be reduced so easily," Hemenway wrote.