Police announced their presence on Brooklyn bound R train Tuesday before briefly peeking into the car, looking for any signs of trouble.
The initiative is part of a surge of 644 officers now headed into the transit system after the rash of violence that culminated with several stabbings on opposite ends of the A line this weekend.
Two victims died, one in Far Rockaway and the other in Inwood.
Police say they used surveillance video and a victim's statement to track down 21-year-old Rigoberto Lopez, a homeless man with a history of mental illness.
Lopez was arrested still holding the alleged murder weapon and with his clothes still bloody.
RELATED: Subway stabbing suspect had knife on him when he was arrested
Another man was stabbed on the 1 train platform at Christopher Street last week, and in January, police body camera footage showed the moment someone tried to shove a woman in front of a moving train.
Recent incidents also include a February 3 slashing in the East Village, where Noel Quintana received a face laceration on the L train.
"I was scared because I thought I was going to die," he said. "And nobody helped me."
RELATED | Man slashed across face in subway dispute speaks out, mayor denies crime problem
NYPD Transit Chief Kathleen O'Reilly is promising change.
"The public can expect to see this surge of uniformed presence in the subway system for the foreseeable future, patrolling platforms, securing entryways and riding the trains," she said.
The increase is made possible through a mix of overtime and reassignments, and while many riders appreciate the enforcement, skepticism remains.
"I'm sorry, you can pander all you want and you can say all you want about security measures, but unless the cops actually do something when the stabbers are on the train, then so what?" one rider said.
Another pointed out there are limitations to what the extra security can even handle.
"Someone did, like, spit in a girl's face last night," the straphanger said. "And a cop can't really do anything about that if he's in the station rather than in the train."
Police say they will be riding trains more frequently, and the MTA is calling for even more officers in the subway system.
They say the real crisis has to do with the number of mentally ill people roaming free underground.
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