The killing of NYPD officers Wen Jian Liu and Rafael Ramos will likely force the department to make changes in the timing and content of its massive retraining program underway in the wake of the Eric Garner case, according to law enforcement officials and experts.

With officers angry and grieving over what NYPD Commissioner William Bratton called "the assassination" of the two officers on Saturday, the NYPD may need to delay the next round of retraining and until the immediate shock of the killings abates, said one high-ranking law enforcement official.

"You would have to be tone deaf" not to change the way officers are being retraining following the killings, said the official, who asked not to be identified.

Bratton ordered the nearly 25,000 patrol officers to undergo retraining on the use of force and community interaction following Garner's death in July from an apparent chokehold during an encounter on Staten Island where police said he resisted arrest while allegedly selling loose cigarettes. A state grand jury declined to indict Officer Daniel Pantaleo in Garner's death, a decision that sparked weeks of protests around the city and country.

Officers are supposed to go through a three-day retraining program at the police academy in College Point, Queens. Lectures and demonstrations during the training deal on separate days with policing philosophy, "smart" skills in dealing with the public and tactical skills for use in confrontations and arrest situations.

So far, three precincts have gone through the three-day course and a second group of precincts was to start around Jan. 5. But the police killings may delay the start date, said the official.

But while the NYPD is committed to putting all precincts through the retraining, one policing expert thinks rank-and-file officers won't be receptive to the retraining after Liu and Ramos were killed.

"They are going to have to forget about the training," said former NYPD detective supervisor Joseph Giacalone, who consults and lectures about policing.

Police officers now feel they are under violent siege for the first time since the 1970s when members of the Black Liberation Army killed four officers in New York City, said Giacalone.

In light of the deaths, angry officers may not be receptive to lectures about how to stop the use of profanity, said the law enforcement official. But in the end, the NYPD will have to make adjustments to acknowledge the terrible case and at the same time drive home the message that having good community relations remains important for the long term, the official said.

"You have to get through [to cops] that you are safer by having help of the community," the official stressed.