planes have black boxes. i personally wasn't aware that vehicles have them, too. and in this case, judy's wrangler, like this one, had a black box. >> it did. so i took this one out of a retired police car to show you what they look like. >> in simple terms, when there's an accident, a car hits something, it triggers the black box to start recording information. what did you learn from judy's black box? >> well, uh, the one for this case came back with no data. >> so no data is actually really important. >> in this case it is. >> no data means no crash. the corporal's theory is that jamie slowly and purposely drove his jeep into the creek. the most surprising witness was teri king, the woman at the center of the alleged love triangle. >> i was hoping that when she finally was put under oath in court that she would come clean. >> teri was no longer living with jamie. >> are you wanting to be here