Violent crime in 2018 on the MBTA declined from the previous year, and such crimes have remained at “historic lows’’ over the last three years, thanks to the “dedication of the men and women’’ on the Transit Police force, Superintendent Richard Sullivan said Wednesday.

In a phone interview, Sullivan said the T has seen a 22 percent decline in part one crimes from 2016 to 2018. Part one crimes include homicide, rape, assault to rape, robbery, aggravated assault, burglary, larceny, auto theft, and arson.

The T saw a 5 percent drop in such crimes in 2018 from 2017.

Sullivan said Transit Police in 2016 adopted a “holistic approach’’ to patrolling the transit system, particularly regarding interactions with juveniles. Some 65,000 Boston Public Schools students ride the T to and from school every weekday.

A juvenile services section is staffed by officers and detectives who fan out into the subway stations to interact with young people, Sullivan said. In addition, a group of Boston police and Transit Police officers, along with school and court officials, meet every morning to discuss where to direct patrols.

“It humanizes our interactions with’’ juveniles, Sullivan said. “It’s been extremely fruitful.’’

He said juvenile arrests on the MBTA have fallen by 33 percent over the last three years, even as part one crimes have also dipped.

“Arrest is the last resort when it comes to our young people,’’ Sullivan said.

All told, there were 761 part one crimes on the T in 2018, down from 797 in 2017, according to Transit Police data. The five-year average from 2011 to 2016 was 998, the data show.

In 2018, there were no homicides, no reported rapes or assaults to rape, 91 robberies, 150 aggravated assaults, 11 burglaries, 487 larcenies, 19 auto thefts, and three arsons, according to the data.

All those numbers were down from 2017, except for aggravated assaults, when there were 138, and arsons, when there were two.

Sullivan attributed the 2018 spike in aggravated assaults to a group of teenagers who were targeting “people they were familiar with, for the most part,’’ on the T.

“These aren’t random assaults that generate a lot of fear in people,’’ Sullivan said, adding that authorities brought members of the group “into court numerous times. . . . I think we’ve been successful in mitigating and reducing the harm. We haven’t had any reports of them doing these acts in 2019, nor, I don’t believe, in all of December.’’

He stressed repeatedly that the crime rate compared with the number of riders who use the T each day is “extremely low.’’ Riders take an average of approximately 1.17 million trips on the entire MBTA system every weekday, according to state records.

A T spokesman added that “MBTA vehicles (trains, buses, ferries) make an average of 17,675 trips on an average weekday.’’

“I’m very proud of our officers,’’ Sullivan said. “They’re the number one reason for [the low numbers]. They’re professional, dedicated, and committed to providing the safest transit environment we possibly can.’’

Transit Police regularly update the public on people being sought in connection with crimes on MBTA property, as well as arrests.

On Tuesday, the department posted surveillance photos on its news site of a man described as a person of interest in an indecent assault and battery that occurred the day before at the Wonderland station in Revere.

Travis Andersen can be reached at travis.andersen@globe.com. Follow him on Twitter @TAGlobe.