Here are some of the main suspects and the evidence against them:
* Ethan: He was Derek's rival and had a motive to want him out of the way. He also disappeared after Derek's death, adding to suspicion.
* Emma: She was the last person to see Derek alive and had a complex relationship with him. She also had access to the murder weapon.
* Rebecca: Derek's mother had a strained relationship with him and was angry at him for stealing from her. However, she also seemed genuinely upset about his death.
The ambiguity surrounding Derek's death adds to the mystery and suspense of the series. It forces viewers to consider different possibilities and analyze the evidence to draw their own conclusions.
Ultimately, the answer to who killed Derek remains open to interpretation. This is a common tactic in TV series, leaving fans to debate and speculate long after the show ends.