As others have said, it depends on the case and the location. At my store it generally went like this:
Uncooperative, no identification, repeat subject, alert or over $100 in merch=automatic call to the police, and the person was usually arrested
Cooperative, merchandise under $50, no priors=recover the merchandise, trespass order and civil demand (basically like a fine that the person has to pay to Target) but no criminal charges
Then there were the people who fell into that $50-$100 category, where it could go either way. These were dictated entirely by attitude.
There are of course some special cases where we HAVE to call the police, for example if someone under 21 was caught stealing alcohol, they had drugs or something else illegal on them, or they are a minor and they didn't have parents that could be contacted.
The major takeaway here is that even the people who are released without police involvement still suffer consequences. They still are banned from the store, they obviously don't have the merchandise they tried to steal, and they receive a bill in the mail from Target. We also take down all their information and enter it into the computer so we can identify them in the future. For example, we had one subject who we apprehended and released. Then, two weeks later, a Dyson went missing. I reviewed video and saw the same guy come in and steal it. We already had his information from the previous case, so we called the police and they put out a warrant for him.