Can a defendant appeal against the exclusion of evidence that supports his claim that the police failed to investigate other suspects?

^4. Defendant here and in a number of other claims urges that the error or misconduct he is asserting infringed various rights guaranteed by the federal and state Constitutions. What we stated in People v. Boyer (2006) 38 Cal.4th 412, 441, footnote 17, applies here: "In most instances, insofar as defendant raised the issue at all in the trial court, he failed explicitly to make some or all of the constitutional arguments he now advances. In each instance, unless otherwise indicated, it appears that either (1) the appellate claim is of a kind... that required no trial court action by the defendant to preserve it, or (2) the new arguments do not invoke facts or legal standards different from those the trial court itself was asked to apply, but merely assert that the trial court's act or omission, insofar as wrong for the reasons actually presented to that court, had the additional legal consequence of violating the Constitution. To that extent, defendant's new constitutional arguments are not forfeited on appeal. [Citations.] [] In the latter instance, of course, rejection, on the merits, of a claim that the trial court erred on the issue actually before that court necessarily leads to rejection of the newly applied constitutional 'gloss' as well. No separate constitutional discussion is required in such cases, and we therefore provide none."

^5. To the extent defendant contends the proffered clues indicated a possible bias by the investigators (for failing to investigate possible other suspects), the clues were not relevant to proving a material fact regarding defendant's culpability. (See People v. Hamilton (2009) 45 Cal.4th 863, 913-914 [witness's belief that the police should have investigated another suspect does not establish that that suspect was a viable one].) To the extent defendant contends the exclusion of this evidence violated his right to present a defense during the penalty phase, for the reasons stated, none of the proffered evidence created a lingering doubt by suggesting someone other than defendant was responsible for the murder. (See id. at pp. 911-916.)