A defendant’s graffiti, scribbled on the walls of a St. Clair County holding cell ahead of his criminal trial, was not fair game for prosecutors to share with jurors.In an 11-page unpublished order issued last week, the 5th District Appellate Court affirmed St. Clair County Associate Judge Julia R. Gomric’s decision to suppress the images, finding the graffiti was irrelevant to Samuel Johnson’s consciousness of guilt on a first-degree murder charges.Johnson is accused of fatally stabbing a hairdresser and …