An 18-year-old is behind bars after officials said he threatened Fulton County Sheriff Patrick Labat and his wife over a sprawling gang indictment charging more than two dozen people, including rapper Young Thug.

Quartavius Mender was booked into the Fulton jail last week on 23 charges of making terroristic threats, records show.

Warrants allege the teenager threatened on social media to kill Labat, his wife Jacki and the Atlanta Public Schools police chief. The threats were made following the high-profile arrests of several alleged “Young Slime Life” gang members, a spokeswoman for the sheriff said. Among those charged last month are popular Atlanta rappers Young Thug and Gunna.

Authorities said Mender threatened to kill the Labats on their respective Instagram pages unless Young Thug, the alleged leader of YSL, was released from jail.

“#freethug or Imma sh00t u and your wife,” the teen wrote, according to his arrest warrants. Mender allegedly wrote on the sheriff’s page a second time hours later, saying, “Imma assassinate you.”

He is also accused of announcing plans to kill the sheriff on the Georgia State Patrol’s recruiting page, the Gwinnett County Sheriff’s Office account and the Fulton Clerk of Court’s Instagram page, warrants allege.

Among the 28 people charged in the racketeering indictment is a defendant named Tenquarius Mender. It wasn’t immediately clear Friday morning if he and the teen accused of making the threats are related.

“We take these kinds of brazen threats seriously,” Labat said in a statement. “Social media cyberbullying, and hiding behind a keyboard, will not protect someone from criminal prosecution.”

Mender is being held without bond.

Young Thug, whose real name is Jeffery Williams, was denied bond Thursday after a Fulton County judge expressed “significant concerns” about letting him out.

Prosecutors said they plan to offer plea deals to some of the defendants in exchange for testimony, but that some of their witnesses are already being threatened.

“We have evidence and information of even more threats,” said prosecutor Don Geary, who told the judge one defendant made threats using a contraband cellphone inside the jail. “Our witnesses in this case are being threatened with violence, serious violence and death.”

Geary said he didn’t think Williams had killed anyone personally, but that “he probably has others do it for him.”

Atlanta rapper Young Thug, whose real name is Jeffery Williams, awaits a virtual court appearance following his May arrest.

Credit: arvin.temkar@ajc.com

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Credit: arvin.temkar@ajc.com

Williams is charged with racketeering and participating in gang activity, but prosecutors allege the Grammy winner had a hand in more serious crimes, including murder. His attorneys strongly deny the allegations, and presented witnesses Thursday who testified about the star’s charitable contributions in the southwest Atlanta community and beyond.

Geary told Judge Ural Glanville that granting bond in the case would likely lead to some of the state’s witnesses being threatened or worse. Some potential witnesses have already expressed fears about retaliation, the prosecutor said.

“If they crossed him, he would kill them and their family,” Geary said in court. “They were very clear about that.”

Before denying bond to Williams, the judge read a text message the rapper allegedly sent to fellow YSL members in a 2015 group chat: “Anybody goes into a courtroom and tells the God honest truth they’ll be (expletive) killed.”