CINCINNATI -- Holders of a concealed-weapons permit now may keep a gun hidden in a vehicle as long as they're carrying it in a secure holster, one of several changes to Ohio's concealed-carry law taking effect today.

The law previously required the gun to be in plain sight.

Permit holders also may bring a gun onto school grounds as long as they are in a vehicle picking up or dropping off a child.

Law-enforcement officials say the changes are common sense.

"The more law-abiding people that have guns, the better off we are," Hamilton County Prosecutor Joe Deters said.

"Because the bad guys always have guns," he added. "You look at these school shootings or church shootings -- the ones that have been stopped, it was because someone there had a gun."

The changes also allow holders of valid liquor licenses who are have concealed-weapons permits to carry a hidden gun on their premises.

In addition, the new law removes the burden of proof from a person who hurts or kills an intruder. The new law includes the presumption that a resident acted in self-defense or in defense of another if an intruder has entered unlawfully or without permission.

In debates over the change in the burden of proof, the Ohio Coalition Against Gun Violence expressed concern that the change would lead to more people taking the law into their own hands, regardless of the circumstances.

Most county sheriffs said they have not had trouble with permit holders.

"By far, the vast majority of permit holders are law-abiding people," said Sgt. Monte Mayer, spokesman for the Butler County sheriff's office.

"They are getting the training, doing things the way they should under state law."

Between 2004 and 2007, more than 108,000 people in Ohio received licenses to carry a weapon. Last year, the third full year of the law, Ohio sheriffs issued 22,103 licenses, an increase of nearly 18 percent from the previous year.

Permit holders must not be felons, must undergo a criminal background check and safety-training course, and must pass a test. People who carry a concealed weapon without a license can be prosecuted.

The changes will make the concealed-carry law easier for citizens and police to interpret, said Clermont County Sheriff A. J. Rodenberg.

"But stand by, because ... some new issue will come up, and there's a possibility of even further changes if that happens," he said.