Honestly, I'd have to know what all of the laws are out there.
Personally, I'd be a terrible security guard because I'd just see it as an excuse to kick the shit out of someone if they were shoplifting. At a minimum, future thieves would be saying to each other, "Don't be the guy who gets caught."
Unless I couldn't, of course. There's a lot that can depend on various laws, such as using a, 'Reasonable amount of force.' The whole thing is intricate enough that you have to be really careful lest your location (or even you, personally) become the target of a civil suit...even a criminal suit if you are the employee. Here's a brief overview of shopkeeper's privilege:
https://makemeclever.com/shopkeepers...-business-law/
Let's take it point by point:
Our first item already creates a potential problem for the business, vis-a-vis potential for civil suit. Perhaps one of our resident attorneys will correct me if I'm wrong, but immediately, it occurs to me that one can subject oneself to potential civil liability based on whether or not the shopkeeper is adjudicated to have had, 'Reasonable grounds.' Just that wouldn't be enough for a civil suit, I don't think, but could depend on other particulars such as...did you make physical contact with the individual, did you physically restrain the individual, did you prevent the individual from leaving for an unreasonable period of time, etc...
This is basically the same as above, with the added caveat that, if you are adjudicated NOT to have had reasonable suspicion (in the event of a lawsuit) now you might have committed a hate crime if it is determined that you aggressed and/or restrained an individual based on racial (or other) profiling.
3. Reasonable force and duration: While exercising the shopkeeper’s privilege, store owners or employees are generally allowed to use reasonable force to detain the suspected shoplifter. However, the level of force used must be proportionate to the circumstances, and excessive force is not permissible. The detention should also be for a reasonable duration and should not extend beyond what is necessary to investigate the situation or involve the appropriate authorities.
What are reasonable force and reasonable duration? Perhaps some jurisdictions quantify duration, but, 'Reasonable force,' is defined here as:
https://www.lawinsider.com/clause/the-officer
Reasonable force means that force which is objectively reasonable under the circumstances and the minimum amount of force necessary to effect an arrest or protect the officer or other person.
First of all, what could, "Objectively reasonable," even fucking mean? There is no objectively reasonable. Anyone looking at the level of force used would be determining whether or not it was too much based on their subjective analysis of the event in question.