We begin with the new twist in the trial of a Michigan man who fatally shot an unarmed woman on his porch. Jurors got to see dash cam video after Theodore wafer killed renisha Mcbride. He claims he... See More
We begin with the new twist in the trial of a Michigan man who fatally shot an unarmed woman on his porch. Jurors got to see dash cam video after Theodore wafer killed renisha Mcbride. He claims he didn't know the gun was loaded and ABC's Alex Perez has the latest. Reporter: For the first time jurors hearing Theodore wafer's voice in the moments after he shot and killed renisha Mcbride talking to a responding officer revealing an explanation that had not been heard before. The gun discharged. I didn't know there was a round in there. Reporter: An accident. Until now he maintained he intent intentionally fired fearing for his own life when 19-year-old Mcbride ended up on his porch, drunk and pounding on his door in the middle of the night last November. I don't get it. Who'sing knowing on your door? Reporter: This new account could be a hurdle for the defense. You're now saying it was a mistake. That's a different kind of defense. Prosecutors are either going to argue he's not to be believed about what happened or you can believe him and his conduct was still so incredibly reckless that he should still be found guilty. Reporter: Mcbride's mother and family overcome with emotion Thursday walking out of the courtroom choking back tears as prosecutors showed jurors photos of their daughter's body at the scene. Another difficult moment for the Mcbride family, the prosecutor holding the shotgun that killed renisha, but defense attorneys argue the gun and other evidence was mishandled including the collection of that screen door wafer fired through. And that was one, two, three, four, five, six, seven, eight, nine, ten, 11 days after the shooting is when you processed this -- On the 12th. Reporter: Charged with second degree murder, wafer has pleaded not guilty. The challenge for the defense is going to be showing that a reasonable person wouldn't have just defended himself, but would have shot someone through the door. Reporter: If convicted of second degree murder, wafer could face life in prison. Testimony resumes here at the courthouse on Monday.
This transcript has been automatically generated and may not be 100% accurate.