Sounds like the Owner held a suspect for police.
The suspect happened to be 13 and had fled to a nearby store.
Problem is, the owner went beyond a justified citizen’s arrest when he aimed the apparent weapon at other citizens. He might be able to justify acting if the kid really had thrown a broken bottle and had been a danger to customers in his store but once outside the store he’s no threat, time to call police and let them handle it. Waving a ‘gun’ at third parties who could be packing real heat is stupid.
How did the bottle come to be broken and where did the teen find it? What happened before the bottle was thrown? Any witnesses? Or is this a claim the owner just made to justify poor impulsive decision making on his part?