CC 105 and CC 226 — which tell the jurors to rely on their “common sense and experience” regarding their consideration of evidence – have been approved in an appellate ruling. (See People v. Campos (2007) 156 Cal.App.4th 1228, 1239-1241; see also People v. Centeno (2014) 60 Cal.4th 659, 669 [“jurors may rely on common knowledge and experience in evaluating the evidence”].)
In particular it has been held that jurors may rely on their own common sense and good judgment in evaluating the weight of expert testimony presented to them. (People v. Venegas (1998) 18 Cal.4th 47, 80; see also People v. Stoll (1989) 49 Cal. 3d 1136, 1157; People v. Webb (1993) 6 Cal. 4th 494, 524 [laser procedure for visualizing latent fingerprints not subject to Kelly test because the familiar image of the fingerprint makes reliability of the process readily apparent]; People v. Clark (1993) 5 Cal. 4th 950, 1017-1019 [“blood-spatter” tests not subject to Kelly requirements because it is common knowledge that inferences can be drawn from spatter patterns of blood expelled from the human body].)
However, jurors should not be allowed to use their common sense as a standard for deciding whether or not the defendant is guilty. Defining reasonable doubt in terms of “common sense” has been held to be reversible error by the California Supreme Court:
It is sufficient to say, however, that the phrase “common sense” is about as uncertain as any phrase in the language. When one speaks of common sense, he generally means his own sense; and there is no warrant for the unnecessary use of such a term when there is apt language to express the idea of reasonable doubt which has been frequently approved and pointed out as the language proper to be used. For this reason the judgment must be reversed.
(People v. Paulsell (1896) 115 Cal. 6, 12; compare People v. Daveggio and Michaud (2018) 4 Cal.5th 790, 840-841[“It is not reasonably likely that prospective jurors believed that, if selected, they could rely on common sense that exceeded the bounds of reason in reaching a verdict.”].)
While the CALCRIM instructions do not specifically tell the jurors that they may rely on common sense vis a vis the question of reasonable doubt, they don’t tell the jurors not to do so. Moreover, CC 105 and CC 226 urge jurors to rely on common sense and experience in deciding “whether testimony is true and accurate.” In most trials the truth and accuracy of the witnesses is directly tied to the question of proof beyond a reasonable doubt. As the Court recognized in Daveggio and Michaud “[c]ommon sense may provide the premise upon which reason operates.” (Ibid.) Thus, without further instruction jurors could conclude that the standard CALCRIM instructions allow them to rely on their common sense to override the presumption of innocence.
In sum, supplemental instruction and/or argument of counsel may be appropriate to assure that the jurors understand the proper role of common sense in their deliberations.
Even if your common sense suggests to you that the defendant is guilty, you must still presume that the defendant is innocent and vote to acquit unless the prosecution has proved him guilty beyond a reasonable doubt.