Whirlibird, I think the robbers study the patterns of the time we leave and get back everyday. There is a lot of roofers doing new roofs around the area. Since I have been in the construction business for over 30 years I know that there are some that do this and tell others that do the robberies.
One of the stolen ipad had an app that tells you were it is, so when the app was turned on it showed and area called Little Haiti which is were many Haitians live and many of them work with the roofers. Interesting.