Major MBTA crime rose by 15 percent in 2014, driven by a spike in bicycle thefts, car break-ins, and aggravated assaults, according to year-end figures released by Transit Police Thursday. Violent robberies, however, dropped by nearly a quarter.
"By no means were we happy to see that 15 percent increase, but we're committed to getting that number down," said Transit Police Department spokesman Lieutenant Detective Richard Sullivan. "I think Transit Police have one of the toughest law enforcement jobs in the Commonwealth: We police a vast underground city unto itself, that is spread out, and we do it day in and day out."
Major crimes, which include homicide, rape, and assault to rape, robbery, aggravated assault, burglary, larceny, auto theft, and arson, rose 15 percent in 2014 compared with 2013. Larcenies made up the bulk of all crimes and rose by 25 percent, from 507 reports in 2013 to 632 last year. Instances of aggravated assault rose by 35 percent, from 96 reports in 2013 to 130 in 2014. Robberies were down 22 percent, from 187 reports to 146.
The three stations with the most reported major crimes were South Station, Alewife, and Downtown Crossing, according to the statistics.
Most crimes at South Station, Sullivan said, were property crimes driven by drugs.
"It appears the Boston Police have been successful in their efforts to reduce the drug trade in and around the Chinatown area. Unfortunately for us, that element has moved into and around South Station MBTA," said Sullivan. "We are currently addressing that issue, and will take an aggressive stance on any and all illicit drug activity in the station."
Alewife's numbers were driven by car break-ins, he said. At Downtown Crossing, he said, officers conducted decoy operations to catch smartphone thieves, which accounted for about 35 percent of the crimes reported there.
While this year saw a rise in major crimes, Paul Regan, executive director of the MBTA Advisory Board, which provides oversight to the T, noted that data going back to 1999 showed a general trend of decline in reported major crimes. In 1999, 1,321 major crimes were reported; in 2014, 950 were reported.
"Despite ridership growth, there's a consistent decline," he said. The T logs more than 1.3 million riders every day.
In 2014, as it has been every year since 1999, the earliest date for which statistics were available, larceny was the most common reported major crime on the MBTA by a wide margin.
Bike theft made up more than 40 percent of all larcenies, followed by thefts from motor vehicles, which made up about 23 percent, according to the statistics.
"We're pleased — we're ecstatic — that more and more people are using public transportation. Accompanied with that is, a lot of people are riding their bicycles to the train station," said Sullivan. The bike cages at T stops, however, can't accommodate all the bikes, he said, so riders are locking their bicycles to railings or other fixtures where they are easy prey for thieves. And, said Sullivan, some thieves follow bike riders into the cages, which require a card to tap for entry, and then steal bicycles after they leave.
Officials are asking bike riders to ask those who follow them into the cages to see their cards. When the weather warms up, said Sullivan, Transit Police will have plainclothes and decoy operations to catch thieves, and will try to increase the number of bike cages.
Thefts from motor vehicles rose sharply in 2014, and particularly plagued Alewife, Wellington, and Braintree stations. But, Sullivan said, about two weeks ago, Transit Police arrested a man who was attempting to use a credit card he allegedly stole from a woman's car — and the man admitted to "numerous, numerous" car break-ins.
"Since he's been taken into custody, we have not recorded a single motor vehicle break-and-enter," said Sullivan, who declined to name the man because he has not yet been charged with all the break-ins.
The aggravated assaults are harder to figure out, said Sullivan.
"We did a comprehensive analysis of that issue, and what we found is that there's no pattern that we could discern," said Sullivan. Most assaults are not random, he said — they occur between people who know each other.
Robberies dropped, he said, in large part because police cracked down on "Apple picking" — theft of electronics. Highly visible patrols of uniformed officers in trouble spots and an effective ad campaign, he said, made would-be robbers less likely to act, and potential victims more aware of their surroundings.
Less serious crimes, which include a wide range of offenses such as fare evasion, vandalism, trespassing, simple assault, and drug violations, dropped by 3 percent between 2013 and 2014. Fare evasion made up the vast majority of these reported crimes, and had the largest whole-number drop. When fare evasion was not counted, less serious crimes increased by 12 percent.
So far this year, said Sullivan, major crimes are down 4 percent, and violent robberies are down 31 percent.
"Officers are out there working hard, being visible, where they should be, doing what they should do," said Sullivan. "That is driving those crime numbers back down."
Evan Allen can be reached at evan.allen@globe.com. Follow her on Twitter @evanmallen.