Bianca Devins, 17, attended a concert in New York on Saturday night with Brandon Clark, a 21-year-old boy he had known for a few months.
The next day she was found dead in her hometown of Utica, located about 400 kilometers from the US city.
Clark had slit his throat and then uploaded body photos to social media, before being stopped while stabbing himself in the neck, police explained.
The young man was admitted to a hospital and has been charged with second-degree murder.
Images of Devins’ body appeared on Brandon Clark’s account in the encrypted discord app, as well as in 4chan and on his Instagram profile, from where they were deleted, but not before being copied and shared by other users.
An image uploaded to his Instagram account on Sunday morning showed Devins’ body and the caption «Sorry Bianca,» posted The New York Times And Buzzfeed.
According to the latter medium, the photo was still on the net on Sunday night, although it had been placed behind a sensitive content filter. Instagram deleted Clark’s account on Monday.
The images generated outrage at the distribution of such violent content on social media and highlighted the problems that tech companies have to prevent it.
Instagram claimed Monday that it was working with police, using technology and user reports to delete all accounts that were distributing the images.
«We are taking all steps to remove this content from our platforms,» said a Facebook spokesperson, owner of Instagram.
«Our goal is to act as soon as possible. There’s always room for improvement,» he added.
«Our thoughts are with those affected by this tragic event.»
According to the police, Clark also pulled selfies along with the body, covered with a tarp, after the police arrived at the scene.
A «wonderful young woman»
The events took place in Utica, a city about 390 miles from New York.
The girl’s family described her as a «talented artist, a dear sister, daughter and cousin, and a wonderful young woman.»
In a statement uploaded to Facebook, Utica police explained that everything indicates that the couple met on Instagram two months ago.
They used this social network as the main form of communication and their relationship «progressed to become intimate personally,» according to police.
«They had spent time together and knew the families of both.»
The night before the events, they had been together at a concert and they argued when they returned from it, after leaving the venue around 10 pm and heading towards Utica, located almost 400 kilometers away.
After receiving reports from Discord users, police were already searching for the couple when Clark called the emergency services to make «incriminating claims,» as well as alluding to him «going to «hurt himself.»
Similarities with Christchurch
«The online dissemination of graphic images has a grisly similarity to the shootings that occurred in New Zealand just four months ago,» said BBC Technology Reporter Zoe Kleinman.
Difficulties in removing violent material from social media have been seen in other cases, such as the shooting in Christchurch, New Zealand.
«On that occasion, the killer posted a video live on Facebook for 17 minutes as he shot men, women and children in two mosques.
«Facebook was criticized for not removing all traces of the images immediately after the fact,» Kleinman said.
Tech giants have explained that they are developing automated advanced tools to keep their platforms secure.
«But tragedies like this suggest that there is still a long way to go, and that the patience of both its users and global authorities is running out,» Kleinman says.