It's not uncommon for the wizard police to have thrown criminals into the future as punishment for their deeds. This unfortunately produces the situation where the city is constantly receiving criminals from the past.
Also, due to a portentous event known as The Morsley Conundrum (which identifies a time-traveling event horizon approximately 1,200 years in the future) Wizard City also receives a number of time travelers from the future - some criminal, some criminally insane, and some criminally wanting to alter the course of events, paradox be damned.
These peoples all land in a place called The Present. Double-meaning, this title, as it appears to act as a lightning rod for time-travelers, and because more often than not, these folk become fodder for The Steeves. Sometimes, though, they manage to escape into the city and cause general havoc.
CRIMES FROM THE PAST
CRIMES FROM THE FUTURE