dynamite charge
n.— «Judge Katz read the jury what is known as the “Allen charge.” Euphemistically called the “dynamite charge,” it reminds a potentially deadlocked jury of what is at stake if it fails to reach a unanimous verdict and a mistrial is declared.» —“Judge urges jury to break deadlock in Davis-Besse nuclear trial” by Tom Henry Toledo Blade (Ohio) Oct. 30, 2007. (source: Double-Tongued Dictionary)