When Shirley leaned in to listen, Zieler gave him a sharp elbow to his face, causing all hell to break loose. Check out the video ... two bailiffs immediately jumped on Zieler and wrestled him to the ground.
The judge then asked Shirley if he was ok ... and Shirley gave an amusing response, saying, "I'm fine. I used to box. I've taken a lot better shots than that."
As for Zieler, his life is not going to be so fine. He was found guilty of two counts of first-degree murder in the 1990 slayings of Robin Cornell, 11, and her babysitter, Lisa Story, 32. Zieler was tied to the crimes in 2016 after police matched his DNA to the cold case following his arrest for an unrelated assault.
His trial for the double murder began this year and a 12-person jury convicted him. That same jury also voted in favor of the death penalty for Zieler -- and the judge put his stamp of approval on their recommendation Monday after the courtroom kerfuffle.