I will admit that I have a morbid interest in crime and criminal investigations. My brain is happy to think about what nasty things bad guys can get up to. As a fiction writer, that is not only going to be bad, it's going to lean towards pure evil—then take it one step further.
My stories are primarily set in the US, which means I have to spend a significant amount of time getting my head around various aspects of US law and police procedures. With there being differences between federal, state, and country (sometimes even city), it can seriously do the head in.
But the joys of being a fiction writer, I only need to be plausible. Not everything I read about US law will make its way into one of my manuscripts, but some readers might be interested in learning about the technological aspects of US law that I uncovered.
Today, it’s the little quirk associated with looking at an arrestee’s smartphone.