Her name was Bianca Michelle Devins but she was known on 4chan as "Oxychan," presumably an r9k discord kind of fag.
/r9k/ thread about it
/r9k/ - ROBOT9001 » Thread #43262492
https://archive.li/CsJRk
This was the killer's (Brandon Andrew Clark) Instagram
https://www.instagram.com/yesjuliet/ now deleted. He was a huge fag but like many discord degenerates, wished to be special.
He posted pictures of her dead body on discord but they were removed. There appears to be only one version of the picture.
Description: There is a young girl with light brown complexion, brown eyes, and short-cut wild brown hair. She is wearing a black tank top. She is covered in her own blood. There is a severe lasceration to the left-side of her neck, directly at or above the trapezius. It cuts to her windpipe. She is slumped down in the passenger side of a car seat in an unnatural position; the car door handle is visible behind her. Her eyes are half-open and looking in different directions. Her mouth is half-open, baring teeth, which are visibly bloodied. A knife sits next to her in the seat.
This Instagram timeline was also posted with a second picture of the body.
Slide 1 is the body as before, but from a different angle, focusing almost entirely on her bloodied left arm, presumably taken hastily while driving.
Slide 2 is a picture from the driver's seat in a car on the road. There are blurred brake lights and headlights ahead of him. The text reads: "Here comes Hell. It's redemption, right?"
Slide 3: Not present, but based on the context, I think the third picture was the body.
The story was shared by this account which appears to be another fan of Oxychan he knew.
Frame 1: Entices people to open Instagram story by promising new Lil Peep album.
https://kiwifarms.net/attachments/1563187566871-png.842387/
Frame 2: Picture of torso, message: "Thanks to everyone who was good to me. I will miss you all."
Frame 3: Severe cut to left side of neck, pained look, blood everywhere.. Message: "Ashes to ashes".
Frame 4: Bloodied hand outreached to canvas covering body. Message: "I'm sorry Bianca."
Frame 5: Picture of man in same clothing taking a selfie in the mirror of his room. Message: "<<<<< this guy murdered this girlfriend and posted it 👎"
https://kiwifarms.net/attachments/1563187605980-png.842391/
https://www.localsyr.com/local-news-2/homicide-near-boilermaker-course-delayed-race/
Allegedly, a conversation they had that's been posted (Oxychan is "xanax").
Police say the victim [referring to Brandon] remains in critical condition in a medically induced coma and they have not been able to interview him yet
Sister claims they never dated.
https://threadreaderapp.com/thread/1150628706878029824.html Article by Ian Miles Cheong containing alleged texts from Bianca, various screenshots.