The scene on television is of a boy's bedroom. The camera pans slowly across ageless kid stuff: baseball cards, posters, clumps of dirty laundry. Then it zooms in on a small metal object.

"Johnny's got one thing we didn't have when we were kids," a voice says. "Johnny's got a gun."

The public service announcement is part of a new campaign blitz in Virginia urging people to call police if they spot a juvenile with a gun.

The program -- "Kid With a Gun. Call 911" -- was designed to educate people about the state's new law that makes it illegal for anyone younger than 18 to possess a handgun or assault weapon.

In July, Virginia became the first state to make possession of a handgun by a juvenile a crime. The misdemeanor offense carries a maximum penalty of 12 months in jail. A law previously on the books makes it a felony to take a gun to school. Some jurisdictions, including Fairfax and Prince William counties, are seeking to ban the sale of look-alike toy guns to minors.

The state's secretary of public safety, O. Randolph Rollins, recently came to Northern Virginia to publicize the "Kid With a Gun" program, which he called a "rallying cry for disarming our children."

Rollins cited new evidence of the growing problem from the state's Department of Criminal Justice Services:

* In 1987, nine juveniles were charged with murder with handguns. In 1991, the number increased to 44. Last year, it was 38.

* The juvenile arrest rate for murder has climbed 186 percent since 1983.

* In a survey this year of 109 juveniles convicted in Virginia of various offenses, 70 percent said they had possessed a firearm at some time.

"Juvenile violence, especially when it involves handguns, is the fastest-growing and most serious crime problem we face," Rollins said.

Rollins said the juvenile gun law has been overshadowed by another new law limiting handgun purchases to one a month. He stressed that the name of anyone reporting a youngster with a handgun will remain confidential and that callers will not have to testify as witnesses in court if an arrest is made.

Making a report gives police probable cause to search someone, Rollins said. In the few states that have tried the program, there have been few instances of hoaxes, he said.

Rollins said he hopes the posters, bumper stickers and public service announcements encouraging people to call 911 will help disarm children. Though exact figures are unavailable in most jurisdictions, few juveniles have been arrested since the new gun law kicked in, he said.

The "Kid With a Gun" program recently was started in Richmond and Newport News and Henrico and Hanover counties, where police and sheriff's deputies have been instructed to investigate immediately any report of a juvenile with a handgun. Rollins said he hopes the program will spread to Northern Virginia and across the state.

Spokesmen for law enforcement agencies in Fairfax, Arlington, Loudoun and Prince William counties said they already treat any report of a person with a handgun as a priority. When asked about the program, most said they were learning about it through the media. Some said they plan to participate in the program, which primarily involves heightening public awareness about the new law.

According to a report by the Department of Criminal Justice Services last month, the problem of youth violence could get much worse as the youth population enters its next growth spurt.

The report noted that the state's juvenile murder arrest rate in 1992 was at its highest point even though the "at-risk group" -- those from 13 through 17 years old -- was in the midst of a steady decline. That age group is expected to have increased 21 percent from 1992 to 2000.

"The juvenile crime rate has been going up dramatically over the last five years," said Richard P. Kern, the state's top criminologist. "It's been occurring when the 13-to-17 at-risk group is going down. We have crime going up when we don't expect it to."