**Bussiness as usual**

Where are they going to? In our world we already have FTL (Faster Than Law). Criminals can evade justice by car, plane, ship or train. The thing is, where are they going to? Because wherever they go, there will be law agents waiting for them. The only way to escape is going to a place where there is a different jurisdiction that the one you're fleeing from, and they don't have an extradition treaty.

Having FTL engines so simple you can make a DIY one in your garage causes serious troubles with my suspension of disbelief, but even within the premises of your universe, one thing is having a car-like (or small yacht) FTL spaceship and another thing is having a Make-Your-Own-Habitable-Planet-In-Five-Minutes toolkit on its trunk. Yeah, sure, your criminals can flee to the farthest corner of the galaxy. We'll catch them when they come back for more food. 

As you said, life is incredibly rare in the universe. Fleeing to nowhere is just another form of suicide, and criminals rutinely use suicide to avoid the action of justice. You can't prevent that.