The present study examined one opportunity for jury error in capital trials. We measured participants’ comprehension of mitigating, extenuating, and aggravating factors in relation to a vignette about a murder committed by Jason Massey. We hypothesized that participants’ would be unsure of the meanings of these three terms, but that this incomprehension would not play a part in their decision to sentence Massey to death. As hypothesized we found that a significant number of participants did not understand the meaning of mitigating, extenuating, or aggravating factors. Furthermore, out of 149 participants, 101 chose to sentence Massey to death, apparently ignoring the fact that they were unsure about the legal factors measured just prior. Implications for future research and judicial procedure will be discussed.