What factors properly enter into a prosecutor's decision not to charge a defendant under the Equal Rights Act?

factors properly may enter into a prosecutor's decision to charge under one statute and not another, such as a defendant's background and the severity of the crime, and so long as there is no showing that a defendant 'has been singled out deliberately for prosecution on the basis of some invidious criterion,' that is, ' "one that is arbitrary and thus unjustified because it bears no rational relationship to legitimate law enforcement interests[,]" ' the defendant cannot make out an equal protection violation." (People v. Wilkinson (2004) 33 Cal.4th 821, 838-839.)