He said Tuesday that hundreds more will be deployed to Ferguson, where fires and looting erupted Monday night after word that a grand jury decided not to indict a white police officer who fatally shot 18-year-old Michael Brown.
The rest will be in a position to respond rapidly, if needed. Nixon says 700 guardsmen were in the area on Monday night, when more than a dozen buildings were set on fire and otherwise vandalized.
Earlier, the mayor of Ferguson said it was “deeply concerning” that the National Guard wasn’t deployed in enough time to help quell the violence that followed the decision not to lay charges against Darren Wilson.
"Unfortunately, as the unrest grew, and further assistance was needed, the National Guard was not deployed in enough time to save all of our businesses," James Knowles said Tuesday.
"The decision to delay the deployment of the National Guard is deeply concerning," he said.- LIVE | Get the latest updates
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Knowles urged the governor to make available and to deploy all necessary resources to prevent further destruction of property.
Lawyers for the family of Michael Brown today condemned the grand jury process that determined no charges should be laid against Wilson.
"This process is broken," Benjamin Crump said during a Tuesday press conference.
Crump took issue that St. Louis County prosecutor Bob McCulloch called a grand jury to look into the case, and said a special prosecutor should have been appointed.
Crump also said he objected because Wilson, was not cross-examined during the grand jury hearing.
He also called for every police officer to carry a video body camera to ensure accountability
Lawyer Anthony Gray said the grand jury decision was a "direct reflection of the presentation of the evidence."
Rev. Al Sharpton also spoke, saying the Brown family was not surprised by the grand jury decision.
The rioting that began late Monday saw cars and about a dozen buildings burned.
Firefighters were dousing the blackened remains of some Ferguson businesses and at least one was still ablaze Tuesday morning. Some stores that escaped fire had their display windows smashed, but the St. Louis suburb's streets were mostly clear.
The protests were far more destructive than any of those that followed Brown's Aug. 9 death. Authorities reported hearing hundreds of gunshots, which for a time prevented fire crews from fighting the flames.
61 arrests in Feguson
There were 61 arrests in Ferguson overnight, many for burglary and trespassing, St. Louis County police spokesman Brian Schellman said. There were 21 arrests in St. Louis, where protesters broke some store windows along South Grand Avenue, St. Louis Mayor Francis Slay said.
Gov. Jay Nixon issued a statement saying he was calling in more National Guard troops to assist law enforcement in Ferguson, but he didn't say how many additional troops or how long they would remain.
Jon Belmar, chief of the St. Louis County police, said that unless his agency could bring in 10,000 officers, "I don't think we can prevent folks who really are intent on destroying a community."
At least 18 people were injured during the protests, including two who were admitted to Barnes-Jewish Hospital for treatment of undisclosed injuries. That hospital treated and released five people. Six people were treated for minor injuries at Christian Hospital, near Ferguson. Saint Louis University Hospital treated and released another. Other hospitals didn't immediately respond to phone messages and emails seeking comment.
Meanwhile, many area districts cancelled classes out of concern for the safety of students traveling to and from school.
The grand jury's decision means that Wilson will not face any state criminal charges for killing Brown, whose death inflamed deep racial tensions between many black Americans and police.
Wilson's lawyers issued a statement praising the decision and saying the officer, who has remained out of the public eye since the shooting, is grateful to his supporters.
"Law enforcement personnel must frequently make split-second and difficult decisions," the lawyers wrote. "Officer Wilson followed his training and followed the law."
Prosecuting Attorney Bob McCulloch said the jury of nine whites and three blacks met on 25 separate days over three months, hearing more than 70 hours of testimony from about 60 witnesses, including three medical examiners and experts on blood, toxicology and firearms.
"They are the only people that have heard and examined every witness and every piece of evidence," he said, adding that the jurors "poured their hearts and soul into this process."