New York City Mayor Bill de Blasio was slammed for his lackluster response to news of the brutal murders of four homeless people in Chinatown, with critics urging action over words.

“We’re stunned and horrified by this senseless act of violence against the most vulnerable members of our community,” de Blasio tweeted Saturday afternoon. “It flies in the face of the values of our city. We’re keeping the victims and their loved ones in our hearts.”

De Blasio’s critics came out in full force, saying words were not enough due to the gravity of the situation.

The Sergeants Benevolent Association tweeted Friday about the slayings, criticizing de Blasio and his wife, Chirlane McCray, over her pet project to fight mental illness in New York City.

“Hey Charlene[sic] and Bill,” the SBA tweeted. “Hows[sic] that mental health program working out for you in the safest city in America?”

The New York Police Department (NYPD) identified the suspect as Randy Rodriguez Santos, 24, who is also homeless and has a rap sheet containing at least six other arrests including attempted murder and unlawful possession of marijuana, CNN reported.

Santos was arrested early Saturday before he was transported to a hospital for a psychiatric evaluation and DNA evidence gathering.

“The motive appears to be, right now, just random attacks,” Detective Michael Baldassano, Chief of Manhattan South Detectives, told WCBS News Radio 880, adding there was no evidence yet that the victims were “targeted by race, age, anything of that nature.”

The murder charges come after four homeless men died and one was seriously injured early Saturday morning in Manhattan’s Chinatown neighborhood, after the suspect allegedly struck their heads with a metal object.

Investigators discovered a metal object— believed to be a pipe— that was potentially used as a weapon. Santos faces four counts of murder, one count of attempted murder, and one count of unlawful possession of marijuana at his arraignment hearing Sunday.