The Daily Grind Video

Less than a week after Trayvon Martin’s mother and brother testified in court, his father, Tracy Martin, took the stand as a defense witness.

Just moments after the lead investigator in the shooting, Chris Serino, told the court that Martin admitted the screams he heard on the 911 audio were not his son’s, Martin told defense attorney Mark O’Mara this was not true.

“I didn’t tell him that it wasn’t Trayvon.”

Martin says that he did tell Serino that he couldn’t tell if the screams were Trayvon’s, but he never said “no” outright.

In a heartbreaking moment during cross examination, Martin talked about life without Trayvon.

“It’s very difficult to believe Trayvon is not living. As I said over and over, that’s my best friend in life and to have him gone is tragic.”

Watch his testimony above and the emotional cross examination below:

For more details about Day 20 in the George Zimmerman murder trial, click here.