Metro transit officials undercount serious crime at the region's 86 rail stations, leaving dozens of assaults, robberies and other major incidents off the official tally they report to the system's board of directors and the public.

That practice stems from a long-standing policy not to count crimes handled by law enforcement officers other than Metro's Transit Police, even if the crimes occur in a station or on a subway platform.

For the 18 months ending in June, for example, Transit Police recorded 73 aggravated assaults at rail stations, but they did not include the 21 aggravated assaults reported by other police departments, which brings the total up by nearly 30 percent, according to a review of records by The Washington Post.

Nearly 60 percent of the serious crimes at Montgomery County stations did not show up in Metro figures because they were investigated by local police. Montgomery reported 36 incidents, and Transit Police reported 27.

"We don't really have a clue what's going on," said Charles Deegan, who represents Maryland on Metro's board of directors. "Shouldn't I know what crime is on the Metro? I would insist they add everything together to give us an accurate accounting of crime on the system. "

Metro officials say the policy was designed to avoid double counting. Transit Police Chief Polly L. Hanson defended the policy and said crime on the rail system is low. But the day after an interview with The Post, she asked her police counterparts in the region to forward to her reports on crimes they handled on Metro property. She vowed to start making those numbers public.

Board Chairman T. Dana Kauffman said he wants Hanson to change her reports to the board. All Metro-related crime "needs to be captured," regardless of who handles it, he said. "We're not going to do a Kabuki dance over 'this is us and this is them,' " he said.

The current bookkeeping method raises questions about claims by Metro officials that crime has fallen.

In a July news release, Hanson boasted of a 24 percent reduction in aggravated assaults and a 19 percent drop in larcenies between June 2004 and June 2005. According to the department's 2004 annual report, a larger category of crime on the rail and bus system dropped by 2 percent compared with the previous year -- 1,234 crimes compared with 1,259.

During the 18-month period reviewed by The Post, Metro counted 463 serious crimes at its rail stations, but 98 other, similar incidents remained off its books, according to local police department records. That raises by more than 20 percent the total number of serious crimes -- rapes, aggravated assaults, armed holdups, pickpockets and purse snatches.

Thousands of lesser crimes, including vandalism and urinating in public, also occurred on the rail system during that period.

Many of the most serious incidents, however, were not counted in Metro statistics.

At the Rockville station, for example, county police handled eight robberies and two aggravated assaults, and Transit Police reported just one aggravated assault.

At the Columbia Heights Station in Northwest Washington, D.C. police reported 14 robberies and one aggravated assault. Metro reported seven serious crimes.

Among the incidents not included in Metro's tally but recorded by local police:

On Christmas Day last year, a 31-year-old man was thrown to the ground at the Rockville stop by three attackers who took his wallet and fled into the station.

During a morning rush hour last November, a 66-year-old woman who had parked her car at the Landover Station was confronted by two thieves who grabbed her money and car keys, then drove off in her Toyota.

In January 2004, a 19-year-old man was stepping off a bus at the King Street Station when a mugger punched him in the face, demanded his wallet and wrestled him to the ground. Witnesses intervened, and police charged the attacker with assault.

Officials in charge of the nation's second-busiest subway system, behind New York's, have long placed a premium on its image as a safe, secure system, boasting about low crime rates as ridership has soared to record levels.

Few of the system's 730,000 daily riders fall victim to serious crime. Metrorail reported its crime rate last year as 6 crimes per 1 million trips. That figure was higher than the 1.72 for the Bay Area Rapid Transit rail system in San Francisco Bay and the 1.1 rate reported by New Jersey Transit. It was considerably lower than the rate at the Metropolitan Atlanta Rapid Transit Authority, which recorded 33.1 crimes per 1 million trips.

Metro transit officers are frequently assisted by police in the District and surrounding counties, often deciding at a crime scene which agency will take the lead role. When another department takes the lead, Metro does not record the crime in its statistics.

That's what happened after a shooting Jan. 15 adjacent to the Shady Grove Station. A 19-year-old man had just stepped off a bus when a car stopped behind him. A man jumped from the car, yelled in Spanish, fired several shots and drove off.

Metro Transit Police and Montgomery officers raced to the scene, where they found the victim bleeding from his upper body. He was taken to the hospital and survived.

A Metro transit officer was first on the scene, but county police assumed control of the investigation. The transit officer wrote a report for Metro, and Montgomery police also provided information to the rail agency. But the shooting was recorded only in county statistics.

There is no easy way for the public to know the extent of crime at a specific Metro station. That would require requesting records from local and Transit Police, a process that can take months.

The statistics published on the system's Web site reflect aggregate numbers -- not broken down by Metro station -- and include only those collected by Transit Police. After Hanson's interview with The Post, the agency added a line to its Web site that notes that its figures do not include crimes reported by local police departments.

The counting system "presents a false picture of what's really going on," said a 26-year-old accountant who was punched in the face on a platform at the Metro Center Station during evening rush hour in May 2004. The assault was not included in Metro's figures.

"The Metro appears safer than it actually is," said the man, who spoke on condition he not be identified because he had been threatened by the assailant, whom D.C. police charged with aggravated assault.

"I wish the police would disclose all of the incidents, regardless of who made the arrests," the accountant said. The information would benefit riders and help Metro, he said. "If they don't have the full statistics, they can't really enact programs to curb crime or measure how much progress they have made in programs to fight crime."

Hanson said that until now, "no one has ever asked" whether her agency's method of counting crimes was adequate. "I don't know what I don't know," she said. She said she was "very surprised" that incidents handled by other departments would raise the total number of serious crimes by more than 20 percent.

The Post requested statistics on crime at Metro stations from nine local and regional police agencies, including incidents on platforms, in stations, at parking facilities and in bus bays. None of the departments tracks crime at Metro stations separately, but the departments gathered the information by searching databases, for example, and matching addresses. The review did not include the Metrobus system because of the difficulty of tracking incidents at the region's 12,000 bus stops.

Local police reported a range of crimes at rail stations, including incidents involving handguns, box cutters and baseball bats. In one attempted robbery handled by Montgomery police at the Rockville Station, a man fought back by removing his belt and swinging it at his attackers.

Stolen cars and thefts from parked cars are a major concern for Metro, which has 50,000 parking spots at its stations, making it the biggest parking operator in the area.

In July, Hanson reported to the Metro board that the number of stolen cars had dropped 40 percent compared with last year, but she didn't include incidents handled by other jurisdictions.

In the 18 months ending in June, Metro recorded 349 car thefts or attempted thefts. But other police departments reported an additional 50 thefts or attempted thefts, an additional 14 percent.

"When [Transit Police] talked about crime coming down in the parking lots, I thought that was total crime, not just the crime that Metro handles," said Deegan, the board member. "We're bragging about what we're doing, and we're not showing the full picture."

The Transit Police do not count crimes on non-Metro property, even if the victims are Metro passengers using the parking lots -- some of which are not owned by Metro -- pedestrian walkways or other areas adjoining the stations. Hanson, who has described the stations as a safe haven in troubled neighborhoods, said her agency is unfairly tarnished by nearby "street crime."

Late last month, Montgomery police reported five muggings in and around Twinbrook Station. All of the victims were walking home from the Metro, most of them on a pedestrian walkway that leads from the station to a nearby intersection. In most cases, the robbers showed a handgun.

Hanson doesn't consider those muggings to be Metro crimes. "We're not experiencing that crime," she said.

But Kauffman, the board chairman , said Metro should include off-site crimes if they are "reasonably linked" to the station.

Several riders said they find the method of counting crimes confusing because it is irrelevant which police agency handles the crime or who owns the parking lot.

"People just want to be safe," said Nancy Nickell, a Silver Spring resident who relies on public transportation to get to her job as an aerobics instructor. "They don't want some line to be drawn. . . . I wouldn't be on the property if the Metro station weren't there."

Research database editor Derek Willis and staff researcher Bobbye Pratt contributed to this report.

Transit Police do not count crimes on non-Metro property, such as walkways and parking lots, even if the victims are passengers, which upsets some, such as Nancy Nickell, who uses a flashlight at Glenmont Station. "I wouldn't be on the property if the Metro station weren't there," she says.