I had something similar happen to me at the end of last year. Came out of a restaurant to find the passenger rear window broken out and my briefcase stolen. They got my computer and iPad plus some other important stuff.
The parking lot was well lit and had seemingly lots of traffic. I was completely surprised because my black briefcase was stuffed underneath the rear bench. So black briefcase not really visible on black rubber mat under black leather seat bench didn't really make sense.
The cop who took down the report told me that some of these thieves carry little flashlights to shine in. That still confused me, because I think it would still be hard to see, especially if you are in a hurry.
Well, I finally figured out what they did. I think what happened was that they took a handheld scanner out with them looking for electronics searching for wifi of cell communications. I think they scanned and found my iPad and or laptop trying to connect and they knew that they had something to get in my truck.
So FWIW, be careful about leaving cell phones, iPads and other electronics in your truck, especially of they are turned on/standby.
Fires