The security system at the Brink's armored car office sounded 103 times in the first six months of this year. But every time police pulled up to the fortresslike building on 17th Street NE, the outcome was the same: a false alarm.

At 1620 I St. NW -- a 10-story office building downtown -- police responded to 92 alarms during the same period. Each was false.

Throughout the city, patrol cars scramble every day to answer alarms at businesses and homes, and officials said about 98 percent prove false. These calls divert too many patrol cars from more pressing matters, police said. And the assignments are time-consuming: It can take nearly a half-hour to scour a high-rise for signs of intruders.

"It's a big problem because it ties up resources," D.C. Police Chief Charles H. Ramsey said. "We've got some locations where the alarms go off regularly."

The city has about 4,600 burglaries a year, officials said. D.C. police get about 60,000 false alarms a year -- more than half of them from businesses. Ramsey said the city needs to impose "stiff fines" on those responsible for repeated false alarms.

The District has a law that calls for fines of $100 to $800. But the long-standing law has been virtually unenforceable because it created no system to collect the money, police officials said. The D.C. Council, though, might correct that problem soon.

Council members are considering proposals to fine homeowners and businesses that generate three or more false alarms a year. The city would hire a private contractor to collect the fines. Owners of alarm systems also would be required to register with the District and pay annual fees.

Council member David A. Catania (I-At Large) is among those pushing for the penalties. He said police are losing thousands of hours because of faulty alarm systems and other problems. False alarms are 10 percent of all calls handled by D.C. police, officials said.

Many suburban jurisdictions already have cracked down. Officials in Montgomery, Prince George's and Fairfax counties have sharply reduced false alarms by levying fines and encouraging alarm companies to cancel the police run if they discover no emergency exists. In Montgomery, authorities have issued about $500,000 in fines annually, which officials said has contributed to false alarms declining by half in just more than a decade.

Merlin Guilbeau, executive director of the Silver Spring-based National Burglar and Fire Alarm Association, which represents 2,400 alarm companies nationwide, said jurisdictions need rigid rules to battle the problem.

False alarms are triggered in various ways. In office buildings, mistakes by cleaning crews or employees unfamiliar with the systems sometimes set off alarms. Other false alarms stem from old and faulty equipment, inclement weather or power outages, police said.

They also can be caused by the slightest movement, which occurred in at least some of the 52 false alarms at A & D Auto Rental on Bladensburg Road in Northeast Washington during the first half of this year, said Reggie Seifu, chief operations officer.

Seifu said the alarm company told him at one point that a bird inside his shop triggered the movement sensors. But in other instances, Seifu said, the alarm company sent inexperienced people to repair the faulty system, which went off seven times Feb. 21.

"They should fine them, not us," he said.

In the District, as in other jurisdictions, repeat violators account for the largest share of false alarms, police said.

Of the more than 30,000 false alarms received by D.C. police in the first six months of this year, two-thirds came from addresses recording at least three false alarms in that period, police said. Fifteen commercial addresses -- including two schools, three churches, an upscale steakhouse, a fast-food Mexican restaurant and several downtown office buildings -- had at least 50 false alarms in the six-month span.

A manager at the Brink's office, which recorded the highest number of false alarms in the city during the year's first six months, said some of its 103 false alarms were triggered by power outages in the area. He declined to give his name or provide other details.

The management company for the building on I Street NW did not return several phone calls seeking comment. Tenants in the building include law offices, a foreign airline, the U.S. Conference of Mayors and the Society of Flavor Chemists.

D.C. police officials said burglar-alarm runs sometimes take a back seat to more pressing calls. And if an alarm goes off more than three times in an eight-hour shift, supervisors sometimes tell officers to stop responding.

Nonetheless, they said, false alarms can pose dangers to police officers. Patrol officers acknowledge that they do not always display the requisite caution when responding to a flurry of false alarms.

"We go there with more of a lax attitude sometimes when there's a constant alarm at the same location," said D.C. police officer Laura Worthington of the 3rd Police District, which includes parts of downtown and Adams Morgan.

The problem was evident one recent afternoon shortly after police cruiser No. 352 hit the streets downtown.

D.C. police officers Laswaun Washington and Denise Johnson pulled up to an office building in the 1900 block of K Street NW, where an alarm was sounding, only to learn that someone accidentally had hit the panic button in the garage instead of the button that summons the parking attendant. It was a typical scenario, said the officers, who would respond to five more false alarms over the next three hours.

D.C. police Sgt. Joseph Perren, who supervises patrols in the 3rd District, lamented: "It's not fair to us or the community because we could be helping other people on the street or reducing crime."

Staff researcher Karl Evanzz contributed to this report.

Officers Johnson and Washington and security specialist Tim Ellis investigate a false burglary alarm in the 2000 block of K Street NW.D.C. police officers Denise Johnson and Laswaun Washington patrol the 3rd District precinct. The vast majority of alarms in the city prove to be false.