On April 23, 2010, CC 521 was revised. As explained by the CC Committee, “the definition of deliberation and premeditation in [CC No. 521], Murder: Degrees could be misleading in cases in which an extended act, such as strangling or drowning, causes the homicide.” (Advisory Committee on Criminal Jury Instructions, Report to the Judicial Council for meeting of April 23, 2010, p. 4.) The Committee thus changed the word “committing” to “completing” in the last sentence of the instruction, and provided an optional plural form for the word “act” so that this part now reads, “The defendant acted with premeditation if (he/she) decided to kill before completing the act[s] that caused death.”
On February 25, 2013, the CC Committee revised CC 521 again, and also revised the last paragraph of CC 520. The CC Committee explained:
Two judges from the Superior Court of Los Angeles County reported that these instructions are confusing to jurors, because there is no distinct explanation of second degree murder. Apparently, recent revisions to these instructions may not have had the desired effect because jurors continue to ask judges for a definition of second degree murder. The committee considered two different, specific suggestions for clarifying this concept, which prompted the proposed changes in the current drafts. When the proposed changes circulated for public comment, several commentators stated that they found the change to [CC 521], First Degree Murder, confusing because they believed the proposed language suggested jurors would need to find the defendant guilty of second degree murder if they determined that defendant was not guilty of first degree murder.
The committee disagrees with these comments, because jurors hear and interpret the instructions as a whole, and not in isolation. Jurors hear [CC 520], First or Second Degree Murder with Malice Aforethought, immediately before hearing [CC 521]. [CC 520] guides jurors in deciding whether the defendant committed murder, regardless of the degree. The purpose of [CC 521], First Degree Murder, is to walk jurors through the process of determining whether any murder committed is of the first degree, as the third paragraph of the instruction indicates. Any murder that does not meet the requirements for first degree murder is by default a second degree murder. Jurors will also hear either [CC 640] or [CC 641], the instructions about lesser included offenses when a defendant is charged with first degree murder. These instructions guide jurors through the decision-making process in careful detail. (Advisory Committee on Criminal Jury Instructions, Report to the Judicial Council for meeting of February 26, 2013, pp. 2-3.)