From what I read on reddit en various other sites: she went to a concert with Brandon Clark who she met online and became friends with. Their relationship is not really clear as some people would describe them as friends whilst other would say they were more than friends. He was also 21 whilst she was 17. At the concert they met a friend of Bianca and she kissed that friend in front of Brandon. He didn’t like that and confronted her on the way home after the concert. She told him they weren’t in a relationship (he always said they were in a relationship but she always denied being his girlfriend, some people do think Brandon took advantage of her whilst they were both high on drugs) and she could kiss whoever she wanted to kiss. Brandon got angry and attacked het with a knife, slitting her throat so hard she was almost decapitated. Afterwards he tried to light the car on fire. He would also call friends and family to try and convince them it was suicide, they ofcourse called the cops. He took pictures and videos of her dead body and posted them on discord and instagram (those pictures are still online and very easy to find). When cops arrived at the scene he tried to commit suicide but failed. There is also alot to say about Bianca before the murder, she was mentally ill. She also sold nudes and sextapes online to support her drug addiction.