The singer said she understands "that it's not at all funny"
On Sunday, Grande’s friend Doug Middlebrook shared an Instagram photo of JonBenét on a newspaper cover, along with the caption: “No one has done more covers.”
Grande, 26, commented, “I can’t WAIT for this to be your halloween look,” to which Middlebrook wrote back, “Working on it already.”
Grande quickly found herself in hot water with many social media users calling her out on Twitter and re-posting her since-deleted comment.
Middlebrook has also deleted his post.
“I need people to stop with this strange, very unnerving JonBenet Ramsey obsession. Jeffree Star has her tattooed on him. Ariana Grande is endorsing her as a Halloween costume. She is not a character or celebrity. She is a little girl who was murdered. It’s cruel and gross,” a tweet read.
“Ariana Grande & her friend doug make a joke about the tragic death of a child that was abused, tortured and murdered was so immature and cruel,” a different user expressed.
“Wait WHAT?? an 8-year-old girl who was violently killed, strangled and suffocated cannot be anyone’s costume,” one user wrote alongside screengrabs of both Grande’s comment and Middlebrook’s post.
Grande later responded to the tweet, writing, “yeah no i deleted it very quickly and understand that it’s not at all funny. this was out of pocket and i sincerely apologize.”
Nonetheless, fans admitted they were still disappointed in Grande for not realizing the gravity of the situation sooner.
“Girl it was up for a whole day… u didn’t delete it ‘very quickly,'” one user said of the comment.
A rep for Grande did not immediately respond to PEOPLE’s request for comment.
In their Boulder, Colorado, home on the morning of Dec. 26, 1996, parents John and Patsy Ramsey found a ransom note handwritten on a pad with a black Sharpie that belonged to the family. It demanded $118,000 — the exact amount of a bonus recently received by John — for the return of JonBenét.
Later that morning, JonBenét’s body, beaten and strangled with a garrote around her neck and duct tape covering her mouth, was found in the basement of the family’s Tudor brick home.
Police are still looking for the killer.
At least 37 books have explored the crime, along with at least a dozen TV programs and movies. None have helped resolve the cold case.