The subway crime that Jimmy Sumampow had been hearing about in recent years — as well as his own experience — had already led him to make plans to leave New York City. Then, on Friday, he saw a video online of the shooting on an A train this week.

“I’m scared,” said Mr. Sumampow, 46, after seeing the video. Mr. Sumampow lives in Elmhurst, Queens, but plans to board an Amtrak train on Monday for Florida, where he has a new job and an apartment lined up. “I feel I should move out for a while and see if New York takes action and gets better,” he said.

For Elise Anderson, however, the shooting did not raise her level of concern.

“I wouldn’t say I’m any more scared,” Ms. Anderson, a 27-year-old Brooklyn resident, said as she waited at the Port Authority Bus Terminal subway station on Friday for a No. 7 train. “I think we’re in one of the safest cities in the world.”

In interviews across the city this week, New Yorkers wrestled with a question that cut to the core of the city’s identity: Is the subway system safe? Subway crime data in recent years shows a muddled picture, and just as they have in surveys of riders and polls of residents, New Yorkers’ opinions diverge.

But barely more than a week after Gov. Kathy Hochul sent the National Guard and State Police into the subway to increase security and help ease New Yorkers’ fears, the shooting seemed to underscore the limits of law enforcement’s ability to improve safety underground.

The shooting took place seconds after the train arrived at the Hoyt-Schermerhorn station, where the Police Department maintains an outpost, Transit District 30, that is regularly staffed by officers. Moments before the shooting, two additional officers entered the station to inspect the platforms and train cars, Kaz Daughtry, the Police Department’s deputy commissioner of operations, said at a news conference on Friday.