Background: Witness 8 was a friend of Trayvon Martin. Her name has not yet been revealed.

Involvement in case: Witness 8 says she was on the phone with Martin when he encountered George Zimmerman in Sanford. She was interviewed by Martin family attorney Benjamin Crump, who recorded the interview and played it at a news conference in 2012.

In March 2013, prosecutors told a judge that Witness 8 said that she was at a hospital during Martin's funeral. The defense then sought her medical records, to which the state conceded there were no records to show she was in the hospital.

Another discrepancy is the age of Witness 8. Martin family attorney Benjamin Crump had previously said the witness was 16 years old. But prosecutors have since said she was already 18 -- legally an adult -- on the night of the killing, February 26, 2012.