Joinder and severance
Mandatory Joinder
Permissive Joinder
Connected together in their commission
Different statements of the same offense
Same class
Same class is "offenses possessing common characteristics or attributes". (People v. Kemp (1961) 55 Cal.3d 458, 476.) It does not mean two offenses within the same Title headings in the Penal Code, such as "Crimes Against the Person". (People v. Frank (1933) 130 Cal.App.212.)
=Penal Code section 954
An accusatory pleading may charge two or more different offenses connected together in their commission, or different statements of the same offense or two or more different offenses of the same class of crimes or offenses, under separate counts, and if two or more accusatory pleadings are filed in such cases in the same court, the court may order them to be consolidated. The prosecution is not required to elect between the different offenses or counts set forth in the accusatory pleading, but the defendant may be convicted of any number of the offenses charged, and each offense of which the defendant is convicted must be stated in the verdict or the finding of the court; provided, that the court in which a case is triable, in the interests of justice and for good cause shown, may in its discretion order that the different offenses or counts set forth in the accusatory pleading be tried separately or divided into two or more groups and each of said groups tried separately. An acquittal of one or more counts shall not be deemed an acquittal of any other count.
Unfortunately, courts have interpreted this quite broadly. A lot of crimes are considered in the same class of "assaultive crime against the person". Rape, robbery, and kidnapping are all the same class of assaultive crimes against the person. (People v. Rhoden (1972) 6 Cal.3d 519.) Even felon in possession is an assaultive crime against the person. (People v. Thomas (1990) 219 Cal.app.3d 134.) There are some crimes that not of the same class. Under the influence of a controlled substance is not in the same class as murder. (People v. Merriman (2014) 60 Cal.4th 1, 37.) Robbery and joyriding are not the same class. (People v. Reiner (1957) 148 Cal.App.2d 516.)