What is the current state of the law on conflicts of interest?

"'It has long been held that under both Constitutions, a defendant is deprived of his or her constitutional right to the assistance of counsel in certain circumstances when, despite the physical presence of a defense attorney at trial, that attorney labored under a conflict of interest that compromised his or her loyalty to the defendant.' [Citations.]" (People v. Doolin (2009) 45 Cal.4th 390, 417.) Such a conflict exists when attorney's loyalty to, or efforts on behalf of, a client are threatened by his or her responsibilities to another client, a third person, or his or her own interests. (People v. Cox (1991) 53 Cal.3d 618, 653.)

Claims of Sixth Amendment violations based upon conflicts of interest fall under the category of ineffective assistance of counsel claims, and thus are subject to the test enunciated in Strickland v. Washington (1984) 466 U.S. 668, 688, which requires a defendant to show that (1) counsel's performance was deficient and (2) there is a reasonable probability that, absent counsel's deficiencies, the result of the proceeding would have been different. The deficient performance element is satisfied when the defendant shows that defense counsel labored under an actual conflict of interest which affected his or her performance. (People v. Doolin, supra, 45 Cal.4th at p. 417, citing Mickens v. Taylor (2002) 535 U.S. 162, 166, 171.) A presumption of prejudice arises when defense counsel actively represents conflicting interests. (People v. Doolin, supra, 45 Cal.4th at p. 418, citing Mickens v. Taylor, supra, 535 U.S. at p. 166.)