To the academicians and intellectissimas of the Straight Dope:
Today, as I waited in line at breakfast, I chatted with a police officer, and suggested that today (weather forecast - overcast and rainy all day) was a good day for police work, because most criminal types would stay inside and not cause trouble. She told me that in fact, it was just the opposite - criminals are not deterred by inclement weather, and might even seek it out as the best time to do their dirty deeds because they know nobody will be outside to see them.
If there any support to either hypothesis? In times of great rain or snow or other weather hostile to walking around outside, do crime rates shoot up, go down, or stay about the same?