Americans wanting to buy a handgun will have to wait five days before they can get it starting today in most of the United States when the Brady gun-control law goes into effect.
The law, passed by Congress in November after an eight-year battle, will apply in 32 states and Puerto Rico to give law enforcement agencies time to check gun buyers for criminal records or mental problems.
The other 18 states already have comparable or tougher state laws, including Delaware, Florida, Illinois, Wisconsin and Virginia which all have instant computer background check systems.
Florida has a three-day waiting period and background check.
"Our goal is to see that Brady is as effective as possible at keeping handguns out of the wrong hands," John Magaw, director of the Federal Bureau of Alcohol, Tobacco and Firearms, said in a letter to law enforcement officials.
Opponents led by the National Rifle Association say the law will do little to reduce crime since most criminals get their guns illegally.
The NRA says it plans to file a legal challenge to the Brady law sometime after it takes effect.
"We're going to find it isn't worth the paper it's printed on," said Sen. Larry Craig, an Idaho Republican and a leading gun-control opponent.
"It just puts law-abiding citizens through another hurdle."
Craig said police forces were shifting officers from investigating crime and other duties for background checks.
Supporters say states that already have waiting periods have stopped thousands of gun sales to felons and people with mental problems.
They said the law also provides a cooling-off period for those trying to buy a gun out of anger or depression to kill others or themselves.
The law has strong public support. Fear of violent crime is the leading concern of most Americans according to polls.
The law is named for former White House press secretary James Brady, who became a gun-control advocate after he was shot and crippled in the 1981 assassination attempt on President Reagan.
Brady, in a wheelchair, and his wife Sarah, who heads the group Handgun Control, were at President Clinton's side when he signed the Brady bill Nov.
30 at the White House.
Starting today, anyone who wants to buy a handgun must fill out an ATF form provided by gun dealers, which will be sent to local law enforcement agencies.
Agencies will have five business days to find out if the potential buyer has been convicted of a felony or indicted, is a fugitive from justice or an illegal alien or has been found to be mentally defective or committed to a mental institution.
"If you are advised by an officer that he has reason to believe the purchaser is prohibited from possessing the handgun, the transfer must not be made," ATF told gun dealers.
The waiting period can be waived if the local chief law enforcement officer signs a statement that the buyer needs a handgun immediately because of a threat against the buyer's life or someone in his or her family.
The law expires in five years.