A Metro security report finds that the raw number of crimes across the rail system is down 6.7 percent compared to last year, a drop not nearly as sharp as the ridership decline.

WASHINGTON — The number of crimes on Metro is down slightly compared to last year, but with fewer riders, that means more crime per person across the system.

A Metro security report set to be presented Thursday finds that the raw number of crimes across the rail system is down 6.7 percent compared to last year, a drop not nearly as sharp as the ridership decline. In the bus system, the number of crimes is down almost 30 percent this year over last.

The report also details a 33 percent increase in the number of pickpocketing incidents at stops and on trains and buses, especially of cellphones. That comes as the number of people simply having their phones snatched out of their hands has dropped sharply.

Nearly all robberies in the rail and bus system involved cellphones.

“The devices are small, expensive items, and easy to steal,” the report says.

There also has been a 47 percent increase in the number of crimes in parking garages, including thieves taking everything from pennies and laptops to car parts.

At the College Park garage, thieves stole 15 air bags from cars over a three-month period.

Thefts from cars overall are up 60 percent. In many cases, thieves have smashed in windows.

There are now 5.4 Part I crimes per million riders. Part I crimes include rape, robbery, aggravated assault, burglary, larceny-theft, motor vehicle theft and arson.

Aggravated assaults have increased by about 28 percent compared to last year. In most cases, that means a punch was thrown. More than half of the assaults happened at rail stations in the District.

Bike thefts are down compared to last year by about the same amount Metro ridership has dropped, but the thefts have shifted. In the past few years, more bikes were stolen at Northern Virginia stations than in other areas. This year, the most common spots for bike thefts are Twinbrook and West Hyattsville.