It took less than a day for the first public sighting of the “baby killer,” who was on newly modified house arrest with a 9 p.m. curfew, to make the rounds of social media.

Brooke “Skylar” Richardson, 19, was dining in Miamisburg, Ohio. Several months earlier, the teen had told police that she had given birth to a stillborn baby during the night and buried the body in the back yard near the barbecue pit at her family’s home in nearby Carlisle.

“My husband and I saw the teenage girl from Carlisle who killed and buried her own baby,” a woman wrote on a community Facebook page. “She was at the restaurant we were at, talking on her iPhone. How is someone who is awaiting trial for aggravated murder not in jail?!”

Comments piled up under the post lambasting the former cheerleader, who is out on bail until her trial for murder, among other charges, in the May 2017 death of the baby girl she named Annabelle.

Few details have been released since her July arrest, but the case brought swift backlash in the quiet community. The case has galvanized social media vigilantes, who — bent on seeking “justice” for baby Annabelle — have vilified Richardson as “the monster mom” who murdered a healthy, full-term infant and tried to hide the evidence.

In one Facebook page condemning Richardson, members reportedly took photos of her with her ankle monitor outside her home.

“It’s definitely over the top,” said friend Kiley Alcorn, a 17-year-old student at Carlisle High School. “People are camping outside her house and taking pictures of her. The way people are reacting to it, especially adults, and the whole situation is sad.”

While the exact cause of death couldn’t be determined, the Warren County prosecutor alleges that the recent high school graduate gave birth to a live baby at 32 weeks that she killed, burned and buried.

“It’s divided a lot of people and it’s really sad,” said one family friend, who didn’t want to be named. “The law says innocent until proven guilty and she hasn’t even gone to trial yet and she’s been persecuted in this town and crucified.”

Richardson’s arrest not only stunned the community but friends and family who claimed they didn’t know about the pregnancy.

Based on the timeline that later emerged, Richardson was in her third trimester when she attended her senior prom on May 5, 2017, in a statement-making red gown.

While she posed confidently for photos, the intricately beaded, floor-length dress clung so tightly to the petite athlete’s midsection that some of her friends, for a moment, wondered: Does Skylar look pregnant?

The question, however, didn’t linger in their minds long enough for them to give the possibility any credence. “No, heck no,” one told her mother, who asked about the slight bump while poring over prom photos of the buttermilk-blond teenager, according to a family friend.

Many friends had known her since elementary school and couldn’t imagine their then-18-year-old classmate — whose weight, they say, fluctuated from battling eating disorders — was pregnant.

But less than 48 hours later, Richardson allegedly delivered the baby girl alone in her home.

Justice for Baby Carlisle

The outrage over the case, residents say, is largely relegated online to two private Facebook groups dedicated to hounding Richardson.

Near-daily activity is seen on the pages, with posts that range from the mundane — recent filings in the case — to more salacious, such as the rumored identity of the baby’s father.

This past Mother’s Day was marked in one group with this post: “Happy Mother’s Day to all wonderful moms who choose to keep their kids and not bury them in the backyard.”

Despite their shared mission, the groups are divided over the antics of the page administrator for “Justice For Baby (Annabelle) in Carlisle, Ohio.”

The moderator behind the group, which was created July 24, has reportedly sat outside the Richardson home on at least one occasion to snap pictures, stating that it “doesn’t matter how many hours every day I sit there.” From her parked vehicle, she took photos of the teen, whom she sometimes refers to as “the little princess,” getting in her car or on the lawn, according to members.

“There was a bunch of drama from the leader driving by and taking pictures and posting things and a lot of them were like, ‘That’s not cool,’” a member of the other group, Alisha Harwood, told The Post.

The newer group, which is similarly titled “Justice for Baby Carlisle (Annabelle),” was formed Aug. 7 — the same day Richardson was indicted.

“I try to keep my group as clean as possible with no stalking/harassment and sticking to mostly facts with discussions about opinions and speculation but not direct accusations like the other group,” Tiffany, an administrator for “Justice for Baby Carlisle (Annabelle)” who didn’t want her last name used, wrote in a Facebook message.

More than 1,000 people joined each of the groups, which are composed mostly of adults and recent graduates in Carlisle and neighboring communities. Dozens of members were contacted for this article, the majority of whom either ignored or declined requests for comment, some citing a distrust of the media.

Some members in the “Justice for Baby Carlisle (Annabelle)” group point to Richardson’s supposed privileged background in their comments, suggesting the family was consumed with appearances and that she was driven to kill over fears that a baby would taint their image.

Warren County Prosecutor David Fornshell, who declined to comment on a motive in August, helped fuel that perception at a press conference.

“Skylar and her family, particularly her mother, were pretty obsessed with external appearances and how things appeared to the outside world,” Fornshell said to reporters. “You have a situation where, you know, she’s a cute high school graduate.”

The family lives in a new development near the school with well-manicured lawns. Richardson drove a convertible to cheerleading practice and earned grades that granted her admission to the University of Cincinnati.

Friends, however, adamantly insisted there was more to Skylar than perfectly coiffed blond curls. “These people only know her by her appearance,” said Alcorn, who bonded with Richardson on the cheerleading team. “She drove nice cars, lived in a nice house, but she was a good person on the inside too.”

“The Damage Remains”

When sirens are heard in Carlisle, people “get out their police scanner and they’ll talk about it all night long,” according to a resident. So when police tape went up at the Richardson home, a three-bedroom ranch located around the block from Carlisle High School, the news quickly made waves throughout the close-knit community.

Residents gathered to watch officers execute a search warrant on a July 14, 2017, tip about possible skeletal remains on the property. The teen told her OB-GYN about the stillborn baby during a visit more than two months after she gave birth, prompting the physician to notify police, according to court documents.

Remains discovered in the back yard were sent to the county coroner’s office for further examination. The body, however, would prove to be too decomposed to determine a cause of death.

But before the final report returned, Fornshell charged the teen and declared to the media that the infant was “born alive,” not stillborn as the teen claimed.

Richardson appeared shell-shocked when she pleaded not guilty in the baby’s death at the hearing.

When she returned to court, she was indicted on charges for aggravated murder, involuntary manslaughter, endangering children and tampering with evidence. The teen was also charged with abuse of corpse, according to the indictment, which stated that she treated the body “in a way that would outrage reasonable community sensibilities.”

She was released to her home on $50,000 bond — sparking outraged cries with the hashtag #ThisIsAJoke over the “low” amount.

The social media firestorm only intensified when the prosecutor held a blistering, half-hour press conference on the courthouse steps following the indictment.

“I’m not sure that we will ever be able to provide to you the exact medical cause of death and the reason that is, is because the child was after death burned and subsequently buried,” Fornshell told the media.

The arson allegations were in a preliminary report that a month later was retracted. By then, the press and social media had latched onto them, in part due to Fornshell’s remarks, according to defense filings.

“It’s not because I’m saying that the child was burned alive — however, I am saying that I am not going to be able to stand up here before and tell you to a reasonable degree of medical certainty that the child was not,” Fornshell told reporters.

Two days after his comments, in a rare move, the judge issued a gag order in the case, noting that “each day sees new challenges that jeopardize the guarantee of a fair trial.”

The ban didn’t explicitly mention Fornshell’s press conference, but prohibited him and defense attorneys from speaking publicly about the case.

For seven months, the gruesome narrative that Richardson set the evidence — a baby girl — on fire stood unchallenged, prevailing on social media and in the news, until the gag order was lifted in March.

“She had options and she chose to MURDER that child and BURN it,” one Facebook user wrote. “There is no excuse.”

In court filings, the defense argued that “although this false opinion was subsequently retracted, the damage remains.”

“What started as an 18-year-old high school girl who was frightened and saddened … turned into something sinister and grotesque because of the inaccurate and false opinion by the state’s forensic anthropologist,” the defense wrote.

Days before the trial was set to begin — and months after officials walked back the report — a local news outlet, WXIX-TV, teased an article about the case on social media, writing, “The ex-cheerleader is accused of killing her newborn baby ‘Annabelle’ and burning the remains in her family’s backyard fire pit.”

“Hope someone kills her,” one user wrote in the comments.

Fair and impartial jury

Richardson’s attorneys pushed in March for her trial to be relocated, arguing that the arson allegations tainted the jury pool.

“The damage that was done by the false information has left the public with the horrible mental picture of a girl burning her baby without realizing that version is false, contradicted by science, and retracted by the state’s doctor,” the defense wrote.

The judge, however, refused to relocate the proceedings and went a step further by claiming the defense’s request was “highly inflammatory.”

“The court finds it more than a little disingenuous for a party to seek a change of venue based on pretrial publicity while filing an incendiary memorandum inviting additional and increased media attention,” the judge wrote in court documents.

The defense made another bid to move the proceedings. Nevertheless, Richardson will be joining her counsel at the Warren County Common Pleas Court when the case goes to trial.

“Despite the initial adverse publicity, we hope we can seat a fair and impartial jury,” attorney Charles H. Rittgers told The Post.

The trial is now stuck in legal limbo.

Days before the trial was set to begin in April, the defense filed a motion to throw out a physician’s testimony about the teen reporting the stillbirth, claiming the conversation was protected by doctor-patient privilege.

The judge ruled that prosecutors could call the doctor to the stand, but nothing would be allowed about the teen’s reaction when she found out she was pregnant.

However, if the defense admits her medical records into evidence, the teen will waive her right to doctor-patient privilege, the judge said.

“The judge is saying she can’t have it both ways,” said Professor Stephen Saltzburg at George Washington University Law School. “If her experts want to rely on what otherwise would be privileged, she can’t stop the state. It’s not a one-way street.”

Both the defense and prosecution appealed the ruling, with just three days until jury selection, pushing back the trial as much as eight months.

The trial setback was a disappointment to friends who look forward to closure — despite their increasing concerns over whether the teen will receive a fair trial.

“The town’s already made up their mind,” said a friend, who didn’t want to be identified. “If someone is convinced that she’s a murderer, then their minds won’t change. People are too close-minded to realize what they think may not be the right thing.”

While Richardson has graduated, many of her friends from cheerleading still attend Carlisle High School. Not all have supported her through the case, but they said that students “hardly ever” talk about the trial in class.

The school’s hallways feel considerably removed from the heated environment online. Former classmates said they refrain from gossip “out of respect” for her younger brother, a popular sophomore, and her current boyfriend, who is set to graduate this year.

Her boyfriend, who was her prom date, was never identified by authorities as the possible father, but reportedly has been subpoenaed. Some point to how the couple is still dating as evidence of her innocence.

“He’s stayed with her, so obviously there’s something we don’t know or he would’ve left her by now,” a student said.

Pregnancy rumors had swirled around school during prom season, although friends brushed them off. It’s unclear when Richardson learned she was pregnant, although court documents indicate a physician informed her prior to the birth.

“Nobody knew she was really pregnant,” Alcorn said. “People had suspected it and made rumors that she did, but [they] never came out and said it because she had struggled with eating disorders in the past.”

Those close to the former cheerleader said they’re unable to reconcile the Skylar they know with the one being portrayed in the media and online groups tracking her case.

“She was a teenage girl who worked with kids and loved them,” a friend said. “She had a lot going for her. She wouldn’t do something as evil as everyone says she did.”