Starting in the late 80s some medical doctors at university medical schools started doing research/studies on gun injury, both fatal and nonfatal.  The work involved has (after the start) been paid for by taxpayers via the federal government--specifically the Centers for Disease Control (and Prevention) (CDC) or an arm of that agency, the National Center for Injury Prevention and Control (NCIPC), established in '92.

Unfortunately for the American public, the CDC contracts (grants) have not required that the data collected in these studies be made available to the public or other researchers to permit the professional evaluations that would guard against bogus research.

It's also unfortunate that these research projects have been undertaken without benefit of applicable knowledge that already existed on the topics of the research.  This would be a natural consequence of the fact that the contracts were being placed by people that didn't know anything about violence and criminal use of guns and other weapons, and the studies were undertaken by people who were equally informed.  But, it also appears that much of the deficiency of the research resulted from the fact that the CDC staff and those who received the research grants started with what they wanted to prove:  that guns and gun owners are bad.

The medical researchers found the Journal of the American Medical Association (JAMA) and the New England Journal of Medicine (NEJM) ready to publish reports of their several studies in order to "properly inform" the entire medical community.  Unfortunately again, most of the research has not proved anything near what the researchers and journal editors represent it as proving.  Most typically, the researchers have interpreted flawed results of evidence that two things tend to exist together (the measure being called "risk" as is typical in medical research) as being evidence that one (and always the same one) of the things causes the other.  Of course, the thing they think causes crime, death, injury, suicide, etc. is always EVIL GUNS.

(See the other pages referenced from the pros-cons page and in-home risk page for info on some of the specific claims that were not supported by the actual study results.)

People (including criminologists*, some doctors and even a mathematics class) started writing to the medical journals about problems with the research being reported, even though the only basis on which they could evaluate the research was the reports and letters by the researchers (since the researchers would not release the data they started with).  They also complained about the blatant advocacy of the NEJM editor.  The researchers and NEJM editor lashed out at all criticism and generally tried to portray it as being from the "evil NRA" and its surrogates.

*A criminologist is a professional studier of crime, its causes and relationships of various things to various types of crime.  Criminologists typically work at least parts of their careers in colleges of law and have extensive background in statistics, which is required for the studies they perform.  They often partner with statisticians or academic economists, who also use statistics extensively.