Geisha is writing an essay about the death of Trayvon Martin. As she has researched this event, Geisha uncovered the fact that Martin was wearing a hoodie when he was shot by George Zimmerman. Does Geisha need to reference the source she was reading when she uncovered that information?
Responses

No, because what Trayvon Martin was wearing on the night of his death is not relevant to his death.

No, because the fact that Trayvon Martin was wearing a hoodie is an undisputed fact.

Yes, because although the fact that Trayvon Martin was wearing a hoodie is undisputed, Geisha did not know that fact until she began her research.

Yes, because every piece of information included in a research paper should be sourced.