It was hard to miss Maria Fuertes in her neighborhood. She was 92 years old and could be seen at all hours of day, shoulders hunched, slowly pushing her black cart filled with bottles and cans through the streets of South Richmond Hill, Queens.

On Monday evening, while taking what neighbors described as one of her regular strolls, Ms. Fuertes was attacked just steps from her home by a man who approached her from behind and knocked her to the ground, the police said.

Ms. Fuertes was found lying in the street and later pronounced dead. Investigators are now seeking to determine whether she was sexually assaulted, the police said at a news conference on Friday.

A suspect, Reeaz Khan, 21, also a resident of South Richmond Hill, fled the scene and was later arrested and charged with murder and sex abuse, authorities said.