American Medical Association in 2000 examined the Brady Handgun Violence Prevention Act, a 1994 federal law that established a nationwide waiting period and background check for handgun sales. (The waiting period provision was later removed.)
The study concluded that the law’s waiting period was associated with reductions in the firearm suicide rate for people age 55 and older, but not associated with reductions in homicide rates or overall suicide rates.
Other
research has found that people who buy handguns are at a higher risk of committing suicide during the first week after the purchase. For example,
an article published in 2000 by members of the Firearm Injury Center at the Medical College of Wisconsin said a Wisconsin study found a "sharp increase" in the risk of suicide within one week of a gun purchase.
But
a 2003 report by the U.S. Centers for Disease Control and Prevention that reviewed studies on the effects of waiting periods on violence found that some studies indicated a decrease in violent outcomes associated with the delay, while others indicated an increase.
And a
2012 study by one researcher from the University of Cincinnati and another from Arizona State University found no statistical effects from waiting periods on gun crimes.
In a nutshell, except for suicide, the studies show Wanggaard’s claim about waiting periods and violence is largely correct.