A county grand jury has declined to indict the New Rochelle police officer who fatally shot a schizophrenic 48-year-old man in May.

The shooting of Samuel Cruz, which occurred after his wife called police to their home, saying that he needed medical treatment, became a flashpoint for critics of police tactics and has also led to a $21 million lawsuit against the city and police filed by Cruz’s family.

Cruz was shot once in the chest about 1:30 p.m. May 26 after his wife, Elsa, urged them not to harm him. But shortly after police arrived she heard three loud bangs and the fatal gunshot.

Police said Cruz lunged at them with a knife before they used a stun gun on him twice, apparently to no effect, followed by Officer Steven Geertgens’ fatal shot. Cruz was pronounced dead less than two hours later.

On Tuesday, Westchester County District Attorney Janet DiFiore announced that a 23-person county grand jury had declined to indict Geertgens, who responded with several other officers to Cruz’s home that day. Starting on Nov. 13, the grand jury heard the testimony of 24 witnesses, including Geertgens and four other officers who entered Cruz’s apartment, as well as the 911 recording, 42 crime-scene photographs, autopsy photographs, testimony from ballistics and toxicology experts, and social workers who worked with Cruz.

Finally, on Nov. 22, the grand jury voted not to indict, meaning that, on the criminal side, the case against Geertgens and New Rochelle police is done.

Randolph McLaughlin, a lawyer for the Cruz family, blamed DiFiore’s office for not obtaining an indictment, repeating the common legal aphorism that prosecutors could indict a “ham sandwich” if they wanted to.

“Instead of rendering aid, they rendered death,” McLaughlin, of the Manhattan-based Newman Ferrara, said of the police. “Until these officers are held accountable, these cases will continue to proliferate.”

The Cruz family’s lawsuit, filed in October in U.S. District Court in White Plains, however, will continue. That suit accuses the police of badly bungling the incident and says police waited an hour to give Samuel Cruz medical treatment.

The lawsuit demands an unspecified amount in punitive damages in addition to the $21 million. It also demands that the city reform the way it responds to emotionally disturbed persons.

McLaughlin has pressed civil cases against police departments for several years, including, in White Plains, the fatal police shooting of 68-year-old Kenneth Chamberlain Sr. on Nov. 19, 2011. A county grand jury also declined to indict White Plains police officers in that incident; a civil case against the White Plains and police is pending.

Kathy Gilwit, a spokeswoman for the city, did not respond to request for comment.