What is the test for a jury to convict an appellant of making a destructive device?

Because we hold that appellant's conviction can be sustained on the theory that he intended to make a destructive device, we address here his argument that the jury was instructed on alternative theories of guilt as to the destructive device, one of which was legally correct and one which was legally incorrect. Invoking the rule of People v. Green (1980) 27 Cal.3d 1, 69 (Green), appellant maintains that the prosecution presented two different theories of guilt that he intended to create a destructive device, one theory being a "booby trap" theory, the other a pipe bomb theory. Appellant argues that, as a matter of law, the "booby trap" theory was legally incorrect because the evidence showed appellant intended to detonate a shotgun shell with a mousetrap which, appellant maintains, does not fall within the definition of destructive device under section 12301, subdivision (a)(3). Respondent counters that the prosecution did not pursue alternative theories of guilt but rather argued that all of the evidence indicated an intent to build a destructive device. Thus, where appellant did not dispute at trial certain of the materials found were his and not others and he simply claimed none of the items were his and he did not have the requisite intent to make a destructive device or explosive, whether there were alternate theories or a unanimity instruction is immaterial. We conclude that, even assuming plaintiff is correct that the prosecution pursued a legally incorrect theory of guilt, any error was harmless given appellant's defense and the overwhelming evidence of guilt of the offenses charged.