Posts that a Mercer County man made on Facebook were so concerning that authorities have temporarily seized his firearms, and jailed him on a felony terroristic threats charge, police said.

Hasheem Williams, 27, of Princeton, was arrested Friday in an early usage of a state “red flag” law allowing cops to seize a person’s firearms if they pose "a significant danger of causing bodily injury.”

A tipster who saw Williams’ posts alerted Trenton Detective Sgt. Anthony Manzo, who noticed posts appearing to threaten customers at the Walmart in Hamilton, according to court documents.

“Walmart count ya days tonight,” he wrote in one of the posts, quoted in an affidavit of probable cause filed in Superior Court of Mercer County. “If anybody got sumn slick to sa, say it to me now. I’m about to shut the whole Nottingham Walmart down wassup!"

The Walmart store in Hamilton is on Nottingham Way.

The police turned to the state Extreme Risk Protective Order Act, which went into effect Sept. 1. The law has already snared a Camden County man who allegedly celebrated violence against Jewish people in his online posts. He had also been in contact with the shooter who killed 11 people at a Pittsburgh synagogue last year.

To seize a suspect’s firearms, law enforcement, relatives or roommates must demonstrate to a state Superior Court judge that they believe a person presents “an immediate and present danger to others.”

Williams posted a “homemade” video of someone firing an AR-style rifle and handgun out of a car, and had other posts mentioning an AR rifle and using guns while drunk, court documents say.

His cover photo on Facebook is an advertisement for the Glock Gen5, a line of pistols from the gun manufacturer. Williams regularly posted videos from a shooting range, including one where he mentioned letting a man at the range test out his shotgun.

Other posts threatened someone who stole his car, and mentioned bringing his gun into a Popeye’s restaurant.

“Who ever from North Trenton that stole my car [I’ kill you & your mom b---h,” he wrote in one post.

Trenton police and Mercer County Prosecutor’s Sgt. Joe Angarone went to Superior Court Judge Darlene Pereksta and secured search warrants and an order under the new gun law. They searched a unit in an apartment complex on Albert Way in Princeton and a home on Titus Avenue in Trenton.

Williams was arrested at the Princeton apartment. During the search, cops found five handguns, two shotguns and “numerous rounds of miscellaneous ammunition.” He faces a charge of making terroristic threats, a third-degree offense.

Also working the case were Detective Stewart Owens and Lt. Darren Zappley, of Trenton’s Violent Crime Rapid Response unit, run by Zappley and Manzo.

Federal authorities were alerted of the case and are monitoring an ongoing investigation of Williams, the unit said.

Joe Brandt can be reached at jbrandt@njadvancemedia.com. Follow him on Twitter @JBrandt_NJ. Find NJ.com on Facebook.

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