Shoplifting in wisconsin

The criminal charge is a misdemeanor.  If this is your first offense you will more than likely be given probation and a fine.  Try to get the DA to make it "diversion" which is a special kind of probation.  If you successfully complete it you can have your criminal arrest record cleared.

As for when you can be apprehended, typically, it is at such time as you have exhibited the intent to commit the theft.  So you would not necessarily have to have left the store.  Once you placed the items under your bag intent can be argued.  More than that, in this case they have a video tape of the alleged offense.

As for civil liability:  

943.51 Retail theft; civil liability. (1) Any person who incurs injury to his or her business or property as a result of a violation of s. 943.50 may bring a civil action against any individual who caused the loss for all of the following:
(a) The retail value of the merchandise unless it is returned undamaged and unused. A person may recover under this paragraph only if he or she exercises due diligence in demanding the return of the merchandise immediately after he or she discovers the loss and the identity of the person who has the merchandise.
(b) Any actual damages not covered under par. (a).
(2) In addition to sub. (1), if the person who incurs the loss prevails,
the judgment in the action may grant any of the following:
(a) 1. Except as provided in subd. 1m., exemplary damages of
not more than 3 times the amount under sub. (1).
1m. If the action is brought against a minor or against the parent
who has custody of their minor child for the loss caused by the
minor, the exemplary damages may not exceed 2 times the amount
under sub. (1).
2. No additional proof is required for an award of exemplary damages under this paragraph.
(b) Notwithstanding the limitations of s. 799.25 or 814.04, all
actual costs of the action, including reasonable attorney fees.
(3) Notwithstanding sub. (2) and except as provided in sub.
(3m), the total amount awarded for exemplary damages and reasonable
attorney fees may not exceed $500 for each violation.
(3m) Notwithstanding sub. (2), the total amount awarded for
exemplary damages and reasonable attorney fees may not exceed
$300 for each violation if the action is brought against a minor or
against the parent who has custody of their minor child for the loss
caused by the minor.
(3r) Any recovery under this section shall be reduced by the
amount recovered as restitution for the same act under ss. 800.093
and 973.20.
(4) The plaintiff has the burden of proving by a preponderance
of the evidence that a violation occurred under s. 943.50. A conviction
under s. 943.50 is not a condition precedent to bringing an
action, obtaining a judgment or collecting that judgment under
this section.
(5) A person is not criminally liable under s. 943.30 for any
civil action brought in good faith under this section.
(6) Nothing in this section precludes a plaintiff from bringing
the action under ch. 799 if the amount claimed is within the jurisdictional
limits of s. 799.01 (1) (d).

You should really contact an attorney to help you out here.  They will more likely be successful in arranging for diversion.  Who knows, this is a highly technical area of the law; possibly your rights were violated in some way and they can get the charge thrown out.