What parts of Khalil’s life are shared in the news media, on social media, and in Conversations throughout the book? How does this affect the way different characters perceive his death?

The two major differences in the book are how the media portrays Khalil and how Starr remembers him.
Khalil's Media Portrayal
The media shows Khalil in an incredibly negative light. They focus on his history of selling drugs and imply that he was heavily involved in gang activity. They ignore the fact that he was supporting his mother, and they spend a significant amount of time considering the idea that he did actually have a gun, even though no gun was found at the scene. This causes many characters outside of Garden Heights (Haley, most notably) to view Khalil as a "thug" who got what he deserved.
Starr's Memory of Khalil
Starr remembers Khalil as a funny, handsome, bright young man. She reflects often on their childhood together and the games they played. She remembers that Khalil loved Harry Potter and was her first real crush. She knows the trauma Khalil suffered from his mother's illness and from the loss of Natasha, their childhood friend, to gun violence. She knows that Khalil was getting involved with dealing but also knows his dire financial situation. She also feels guilt around her presence on the night he was murdered.
Starr's memory of Khalil, many elements of which are shared with others in Garden Heights, enhance the belief that is death was a tragic miscarriage of justice.