My wife is always on me to take my shoes off when entering the house.

Now I have a compelling argument for not doing it.

Or not.

I thought this was going to be one of those cases where they linked a whole bunch of open criminal files to the same DNA (same suspect) - but they had no record of the person's DNA on file (which was strange because such an ubiquitous criminal couldn't have gotten away with so many crimes). Until they realized that the guy doing the DNA testing was getting his own DNA in all of the samples thereby screwing up dozens of cases.