TexasCHLforum.com

In the story:
The gun store has cameras, tied to the alarm system. Apparently the window that was broken did not have alarms sensors on it, so the store does not have video of the suspects.

Sounds like it was just luck, on the part of the thieves, or someone knew exactly which window to use to gain entry. Of course it doesn't say whether or not, other windows, were equally, as vulnerable, but it does give rise to the possibility, of an inside job, or disgruntled ex-employee. JMHO