Shoplifting, but not arrested

My girlfriend recently got caught shoplifting at the local mall. She stole a ring and was approached by two security guards. From what she told me, they made up sign a waiver stating that she will not come on the premises for a year and they took a photo of her. She told me one of the guards told me they will be calling her with a court date, however, a real cop was never called in. Can they do this without having a cop book her, or is this a scare tactic. She is very worried and I just wanted to get this cleared up. Thank you very much.

Can they do what? Have her charged with trespassing if she goes back to the mall? Yes. They can also make a police report after she leaves the scene - that may have been what they were describing.