@ Prospective & tc498: She can't sue the store becuase they accused her of a crime. The statements were not defamatory. They had reasonable cause to believe that she committed the crime and filed charges as such, that is not defamation regardless of the trial outcome.

@OP: There is case law, as has been pointed out, that sets a precedence for obtaining a conviction for shoplifting without leaving the premises. The fact that you concealed the items in a shopping back with purchased items and that one of the bags was from a different store will work against you. If you had put them in an empty store bag it would be different. Although the law doesn't state that simply concealing is enough to show guilt, it does not restrict the larceny to by defining it as passing the final point of sale either. Basically the court will decide if there was an intent by you to hide some or all of the items.