Working the midnight shift is like stepping into another world. Even though a police officer has lived and worked in the same location for many years, his environment completely changes when the sun goes down. He wasn't kidding.
Darkness brings a different feel to the air, and it brings out a different kind of person.
I'm not saying that there are fewer crimes committed during the day. On the contrary, some criminal activity, like burglary for example, seems to occur almost elusively during the daytime hours. It is rather a different type of person with a different mindset who comes out at night. Nighttime is when the alcohol and the drugs flow more freely and when people think their activities are hidden by the darkness. At night is when this particular person comes out and seeks trouble.