Is a defendant entitled to additional instructions in the penalty phase of a criminal case where he and his accomplice testify against him?

In addition, we have previously recognized that even if additional instructions may be proper, "a defendant for tactical considerations may not want the penalty phase instructions overloaded with a series of lengthy instructions ... perhaps because he fears that such instructions could result in the jury placing undue significance on such other crimes rather than on the central question of whether he should live or die. In light of these tactical considerations, a defendant who has not requested an instruction ... may not complain on appeal." (People v. Phillips (1985) 41 Cal.3d 29, 73, 222 Cal.Rptr. 127, 711 P.2d 423 fn. 25 [discussing whether jury should be instructed sua sponte on elements of alleged other crimes introduced at the penalty phase].) Defendant's case is similar: delivering the corroboration instructions even after the necessary corroboration must already have been found to exist--defendant having been convicted--might result in a jury placing undue significance on the fact that the accomplice testimony was corroborated, rather than on the penalty issue. Although instructing the jury on accomplice testimony would not be erroneous in this circumstance, it is not required in the absence of a specific request for such instructions.