After a decade on the books, a law banning specific types of firearms, known as assault weapons, expired quietly at midnight Tuesday.

The ban, which was attached to the Violent Crime and Law Enforcement Act signed into law by then-President Clinton in 1994, prohibited the manufacture of 19 specific firearms as well as weapons possessing certain characteristics of assault weapons.

Opponents of the ban have criticized it as an infringement on constitutionally guaranteed rights, while proponents have said the ban helps protect law enforcement officials.

Ashley Varner, National Rifle Association spokeswoman, said the ban hasn’t had much of an effect on the national crime rate. It was irresponsible, Varner said, to keep a law on the books when it only infringes on the Second Amendment.

“Criminals, by definition, don’t go to the dealer to get a gun. They go to the black market,” she said. “So criminals aren’t going to be affected by gun control laws.”

According to FBI statistics, only 1 to 2 percent of total crime in 2004 was committed with an assault rifle. However, 20 percent of those crimes were committed against law enforcement officers.

Leah Woodward, communications director of Iowans for the Prevention of Gun Violence, said such statistics represent a disproportionate number of crimes against police officers.

“We feel they present a threat to this nation’s law enforcement,” Woodward said.

Many people across the nation have been supportive of the ban, she said. Recent polls showed more than 70 percent of Americans supported the ban, she said.

“One of the points we like to make is although such a great majority approves the ban, our legislators have been very reluctant to talk about it,” she said.

Story County Sheriff Paul Fitzgerald, like many other law enforcement officers in Iowa, said he was in support of the ban on assault weapons.

Although many critics have said there are legitimate uses for such rifles, Fitzgerald said there aren’t many situations where it would be appropriate. Critics of the ban have said legitimate uses such as hunting or target shooting are hindered by the law.

“Your typical sportsman does not take an AK-47 into a hunting environment,” he said. “Assault rifles are designed for one purpose — to kill human beings.”

He also said he believed it would be easier for more criminals to get a hold of assault-style rifles with the ban gone. Overall, the effect of the ban would be minimal in this area, he said.

One reason the ban would have little change now that it has expired, critics have said, is because the law dealt with mostly cosmetic differences. Under the ban, if a gun had two or more prohibited characteristics, such as a pistol grip, a bayonet lug or a flash muzzle, it was classified as a banned weapon.

Varner said many banned rifles have nearly the same internal mechanisms and legal rifles, but have different outward appearances.

Both Woodward and Fitzgerald agreed the law had shortcomings.

“If you look at a pre-ban weapon … and you look at a post-ban weapon, they look almost the same,” Woodward said.

One of the goals of the IPGV was to help strengthen the ban to cover more elements, instead of the cosmetic differences, she said.

Fitzgerald acknowledged the flaws in the ban, but thought there was some middle ground that the two sides could agree upon. It was unlikely, however, that any compromise on the issue would be reached, he said.