This is a good point. The jury is SUPPOSED to say, OK, let's balance this aggravating factor--cruelty--against the mitigating factors. She's clearly mentally ill (BPD), but should we count that as mitigating? (Discussion.) What other mitigating factors are there? (Discussion.) OK, juror #4, please try to remember that the pedo lie can be considered only in rebuttal to mitigation, not as an aggravating factor. (Discussion.) Juror #8, I know we all feel terrible for the family, but we cannot decide based on sympathy and must consider the VIS only in rebuttal to mitigation, not as an aggravating factor. Thank you.
Instead, they are quite likely to say, OK, let's list the reasons for death on one side of this paper and reasons for life on the other side. On the death side, premeditation, cruelty, lack of remorse, horrible letter to the family, pedo lie, heart-rending VIS, the irises sent to MumMum, psychopath. On the life side, BPD but only if it's a mental ILLNESS. What does everyone think? OK, it's not a mental illness because it had nothing to do with the crime? OK, I'll cross that off.
Drives me nuts when I interview jurors, because even if they go my way, they invariably have utterly failed to follow the jury instructions.