The unveiling of Frederick's latest crime-fighting weapon wasn't going quite as planned.

Inside the box in the police trailer, wrapped in plastic bags, were several dozen American Defender personal safety whistles: stainless steel noisemakers emblazoned with the Frederick Police Department crest. The department is distributing 450 of them on the theory that residents who are threatened, or who witness a crime, can blow the whistle to alert others or scare an attacker.

On Tuesday night, Michele Davis, a cheerful civilian police worker hoping to set up a heartwarming scene for politicians and the media, suggested passing out whistles to the children of the Sagner housing complex.

"You're joking," said Officer Edward A. Hanner, watching the children bouncing off one another like excited atoms of gas. "The kids are going to run around blowing on the whistles all night long."

Finally, they agreed to supply the whistles only to adults 18 or older. "You can't give these kids whistles," Hanner said. "It'd drive me crazy."

The youngsters and their parents were enjoying chicken and baked beans, along with a moon bounce, at National Night Out, a nationwide picnic to encourage closer ties between law enforcement and residents of crime-troubled neighborhoods.

Outside, Police Chief Kim C. Dine, the architect of the whistle project as well as Frederick's community policing program, arrived just as Snoop Dogg's hit, "Drop It Like It's Hot," began to thump from the speakers. The song, in which the West Coast rapper observes that, "I roll the best weed 'cause I got it going on," also provides advice for listeners confronted by the police:

When the pigs try to get at you,

Park it like it's hot, park it like it's hot, park it like it's hot.

"We're showing our tolerance and communication," Dine said when asked about the music. He quickly changed the subject to the community policing program, which many residents credited with reducing neighborhood crime.

A former D.C. police officer, Dine said that whistles appeared to be unusual in the United States, but that he had seen some plastic whistles given to older D.C. residents. "Is it going to solve all crime in the world?" Dine asked. "No. But it is one more tool in the toolbox."

The whistles, a popular crime-fighting tool in Europe, received a mixed reception from the Frederick residents. They came with bright yellow instruction booklets.

"If you're accosted on the street," the booklet instructs, "1. Blow the whistle. 2. Call the police as soon as possible."

And what if you are accosted by someone with a gun?

Lt. Shawn Martyak, the police's community services head, noted that using the whistle would require a certain amount of common sense. "You have to use it reasonably," he said. "If it's someone with a weapon, you're hopefully going to comply. Without a weapon being present, this is an ideal tool."

The instruction booklet also notes, in confirmation of Hanner's suspicions, that "a whistle, from a child's perspective is a great toy. But its effectiveness will be diminished if children blow the whistle at play."

"Nine times out of 10, you won't even have it with you," said Darlene Cosley, who has lived in the Sagner complex for 26 years. She noted, however, that she probably wouldn't need it: Crime in the neighborhood had gone down in the past couple of years, with a greater police presence in the development and the installation of bright "drug lights" that deny dealers a place to conduct their transactions.

"It's pretty nice here now," Cosley said.

Anita Michels, who has lived in the Mullinix Park community for 15 years, agreed: "I can walk down the street and not feel threatened," she said, saying the drug trade had moved from the area. "There are more police. People are taking pride in where they live and not wanting that stuff around their homes."

As for the whistles, she said, "I think I'd have the presence of mind to use whatever I had available."

Toward the end of the event, which drew a few hundred residents from across the city, Sgt. Charles Combs, chief of the police auxiliary, bestowed one of the whistles on Jasmine De'Jesus, a 10-year-old resident of the Amber Meadows community.

"If somebody starts to harass you or attack you, you blow it," Combs told her.

"Okay," Jasmine said. "What happens when I blow it?"

"It makes a lot of noise," Combs replied.

Jasmine opened the plastic bag but resisted the burning temptation to blow the whistle. She said that if she saw a crime, she would let it rip, or "just run home and tell my dad. And then I'll blow it."

Her friend, Fetreece Hamilton, proved less patient and came over and took the whistle.

"I want to blow it!" she said.

"No!" Jasmine said, snatching it back. "Don't blow it. It's only for an emergency."