mr. donovan then punched yngve raustein, knocking him to the ground. >> narrator: to convict donovan, the prosecution put forth evidence at trial showing donovan knowingly planned and participated in an armed robbery, which started with his punch. >> stay down, stay down... >> narrator: in the course of the robbery, the murder took place, according to the prosecution. >> while raustein was down on the ground... >> narrator: it's a theory of criminal responsibility called "felony murder," which many advocates now say should not be applied to juveniles. >> ...plunged his knife into the chest of mr. raustein... >> in the felony murder scenario where this individual is not directly involved in the killing, the assumption that they know they are walking into a situation where someone could die-- it's actually not scientifically sound to ascribe that same level of foreseeability to a teenager. >> the devastating punch broke donovan's hand as he and velez took raustein's wallet... >> that one punch, i don't know why i did it, right. i also didn't never realize the consequences of what the hell w