A 17-year-old girl with a small social media following in upstate New York was killed by a man she had met recently on Instagram, who then posted photos of her corpse online, police say.
The gory pictures were redistributed widely, including by online posters who made light of or celebrated the teen's death.
Others urged people to stop circulating the images, which had appeared in online chat sites including 4chan and Discord.
On Monday, police identified the slain girl as Bianca Devins, of Utica, New York, and said her alleged assailant, Brandon Clark, was being held on a second-degree murder charge.
Discord users who saw the photos on Sunday morning alerted police.
Officers were trying to find the teen when 21-year-old Clark called 911 to report what he had done, Utica's public safety department said.
Officers who tracked the call found Clark stabbing himself in the neck, causing injuries that required hospital treatment.
Ms Devins' body was under a tarp nearby.
Ms Devins and Clark met on Instagram about two months ago, police said.
Initially, they were online acquaintances only but the "relationship progressed into a personally intimate one", police said.
The two attended a concert together on Saturday night in New York City, where they got into an argument.
They arrived back in Utica early on Sunday and went to a spot on a dead-end street.
There, they argued until Clark used a large knife to kill the teenager, police said.
Authorities began receiving calls on Sunday morning, reporting that a man posted on a social media site that he had killed a person.
After police encountered Clark stabbing himself, he lay down on a green tarp and took selfies lying across the dead teenager before officers took him into custody, police said.
In a statement received by the NY Times, Ms Devins’s family described her as “a talented artist” who, after graduating high school last month, was preparing for college in the fall.
“Bianca’s smile brightened our lives,” the statement said. “She will always be remembered as our Princess.”
A spokeswoman for Instagram said in a statement: “Our thoughts go out to those affected by this tragic event. We are taking every measure to remove this content from our platforms.”
