Does the prosecutor improperly argue that Vo's failure to show mercy to the victim be considered as a factor in aggravation?

Vo next claims the prosecutor impermissibly argued that Vo's failure to show mercy to the victim should be considered as a factor in aggravation. Not so. Pursuant to section 190.3, factor (k), the jury may consider as a mitigating factor "[a]ny other circumstance which extenuates the gravity of the crime even though it is not a legal excuse for the crime." It was in the context of discussing the applicability of this factor to defendants that the prosecutor argued that mercy should not be shown to them in any greater measure than they showed mercy to the victim. The argument was permissible. (See People v. Collins, supra, 49 Cal.4th at p. 230 ["It is not improper to urge the jury to show the defendant the same level of mercy he showed the victim."].)

Vo also contends the prosecutor improperly argued that Vo's age was a factor in aggravation because his youth made him potentially more dangerous in prison. The prosecutor did no such thing. Rather, he argued that both defendants' ages should not weigh in their favor, because they were both adults, because the crime was "monstrous," and because, as Vo's expert told the jury, "age makes them worse prisoners, more dangerous, less controllable in the prison situation." In this regard, it is settled that " 'age' as statutory sentencing factor includes 'any age-related matter suggested by the evidence or by common experience or morality that might reasonably inform the choice of penalty. Accordingly, either counsel may argue any such age-related inference in every case.' " (People v. Williams (2013) 56 Cal.4th 165, 200.) Measured by this standard, the prosecutor's argument in this case was permissible.