One of the ruthless "MS13" ransom gang members fired on a rival on the subway platform, as revealed on Monday.
Councilman Francisco Moya took part in the photographs of the writings and said that he had arrived sometime during the weekend.
"Gangs activity will not be tolerated here," he said in a statement, "residents of this community will not be afraid of the streets in which they walk, the trains they use, or the houses in which they live."
The tag is written in black letters three feet high.
Abel Mosso, 20, was shot dead on Sunday at platform No. 7 at 90th Street in the Moya neighborhood after fighting with another man.
Officials said Mosso was in contact with the 18th Street gang and that the suspect was a known member of M-13, according to New York Police Chief Dermot Chea, who said the incident was "definitely linked to gangs" at a press conference on Monday.