WASHINGTON – While it is an article of faith among gun-control proponents that government restrictions on firearms reduces violence and crime, two new U.S. studies could find no evidence to support such a conclusion.

The National Academy of Sciences issued a 328-page report based on 253 journal articles, 99 books, 43 government publications, a survey of 80 different gun-control laws and some of its own independent study. In short, the panel could find no link between restrictions on gun ownership and lower rates of crime, firearms violence or even accidents with guns.

The panel was established during the Clinton administration and all but one of its members were known to favor gun control.

"Policy questions related to gun ownership and proposals for gun control touch on some of the most contentious issues in American politics: Should regulations restrict who may possess firearms? Should there be restrictions on the number or types of guns that can be purchased? Should safety locks be required? These and many related policy questions cannot be answered definitively because of large gaps in the existing science base," said Charles F. Wellford, professor in the department of criminology and criminal justice at the University of Maryland and chairman of the committee that wrote the report.

However, the National Research Council decided even more thorough research on the topic is needed.

Many studies linking guns to suicide and criminal violence produce conflicting conclusions, have statistical flaws and often do not show whether gun ownership results in certain outcomes, the report said.

A serious limit in such analyses is the lack of good data on who owns firearms and on individual encounters with violence, according to the study.

The report noted that many schools have programs intended to prevent gun violence. However, it added, some studies suggest that children's curiosity and teenagers' attraction to risk make them resistant to the programs or that the projects actually increase the appeal of guns.

Few of these programs, the report concludes, have been adequately evaluated.

The report calls for the development of a National Violent Death Reporting System and a National Incident-Based Reporting System to begin collecting data.

The study by the Research Council, the operating arm of the National Academy of Science, was sponsored by the National Institute of Justice, Centers for Disease Control and Prevention, Joyce Foundation, Annie E. Casey Foundation and the David and Lucile Packard Foundation.

"While more research is always helpful, the notion that we have learned nothing flies in the face of common sense," said John Lott, resident scholar at the American Enterprise Institute and a critic of gun-control laws. "The NAS panel should have concluded as the existing research has: Gun control doesn't help."

Meanwhile, a study released by the Justice Department suggesting background checks at gun shows would do little to keep firearms out of the hands of criminals.

The study noted the number of criminals who obtained guns from retail outlets was dwarfed by the number of those who picked up their arms through means other than legal purchases. The report was the result of interviews with more than 18,000 state and federal inmates conducted nationwide. It found that nearly 80 percent of those interviewed got their guns from friends or family members, or on the street through illegal purchases.

Less than 9 percent were bought at retail outlets and only seven-tenths of 1 percent came from gun shows.