A woman was arrested and charged with second-degree murder on Thursday after an on-duty letter carrier with the United States Postal Service was stabbed to death inside a bodega in Harlemswerteplay, the police said.

Officers responded to a 911 call at 2:38 p.m. about a disturbance at the store, on Lenox Avenue between West 118th and 119th Streets, the police said. They found the victim, Ray Hodges, with stab wounds to his stomach. A knife was found at the store, according to an internal police report.

Mr. Hodges, 36, was taken to Harlem Hospital Center, where he was pronounced dead at 2:57 p.m.

The police arrested Jaia Cruz, 24, hours later on Thursday and charged her with second-degree murder.

The stabbing followed an argument over who was first in line, according to a law enforcement official.

The U.S. Postal Inspection Service, the law enforcement arm of the Postal Service, is working with the police on the investigation.

Charisse Artis, a letter carrier who used to work with Mr. Hodges, went to the bodega on Thursday evening after hearing about the stabbing.

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She described her former co-worker as “very quiet, very laid back,” adding, “Sometimes you didn’t even know he was there.”

Ms. Artis said her first reaction to the news had been to break down in tears. “I told him ‘Happy New Year’s’ this morning,” she said.

In a separate case, another postal worker was attacked Friday morning in East Harlem, according to an internal police document.

A woman hit the postal worker, a 32-year-old woman, in the stomach with an object on Lexington Avenue between 99th and 100th Streets before fleeing south. The postal worker was taken to Mount Sinai Hospital for treatment.

Emlyn Cameronswerteplay, and Alyce McFadden contributed reporting.