She was my best friend (2019)

She was my best friend When one out of five good friends is found dead in her apartment a can of worms is bound to be opened. They came in to resolve a quarrel with her but they found her dead instead of reporting to the police they ran out without making a report not knowing a neighbor saw the way they rushed and left the apartment. The neighbor not satisfied with the awkward movement went to the apartment to check and He found the dead body, made a call to the police and report seeing the four of them left in a rush. The four friends are now the number one suspects for the murder of their best friend. If we are saying the four of them came together to the house and found her dead and the four of them are saying to the police that they did not kill her and they are saying they came together and left together, the question is who could have perpetrated the evil?