This gave me an idea.

http://www.selectadna.co.uk/

Why stop there?  If you are going to spray "synthetic DNA" on someone - which I doubt is DNA at all...but let's move on - why not give the criminals a whiff of something good?   The world is getting too liberal for words.  Teachers can't paddle unruly students anymore - the poor kid needs a hug.  If they GET a hug, the teacher gets arrested for being a perv.

Look, some people are just criminals and psychopaths.  That 13 year-old kid who was in the news last week for having over a hundred felony arrests doesn't need a hug.  He needs to be executed.  So does his mom.  On the other hand, using marijuana is less a crime than using alcohol but the laws are backward and no one seems to be able to roll bad laws back.

Why do people need to put multiple locks on their doors and bars on their windows and install cameras and monitored alarm systems and have yards full of pit-bulls to keep dirtbags out of their homes?  Why are there thirty cameras OUTSIDE Wal-Mart and hundreds inside?  Why do millions of innocent people have to protect themselves from thousands of predators?  The predators ought to be the ones who are worried.  Break in my house, meet Jesus.  Keep walking, no worries.

What would Jesus do?  He had a group of apostles with swords, so that's a good hint.  But swords aren't too effective inside the house, or inside McDonalds, so hipping a short-barreled .357 with you when someone starts knocking on the door is a good idea.  Or at least it is for me, because I don't open the door half the time just to see if someone is checking to find out if someone is home so they can break in. Heh, heh, heh.  

But back to Selectadna.  Why not spray criminals with something non-toxic - you don't want to hurt the poor bastard - but you could dump something on them that would help the police find them and slow their escape at the same time.  In Hawaii, fruit fly pheromone works well.  A million male flies will arrive in seconds from miles away and will fight amongst millions of others of flies to find a spot on the offender's head to copulate with.  They will NEVER leave.  They will crawl up his nose by the hundreds and fly down his throat.  It's really a kick to watch. 

I first thought of it when some bratty kids bothered me once and I managed to get some on one of their heads.  When the flies congregated, the kid freaked out, the other kids ran away screaming, and I started pointing and shouting that the kid had been possessed by Satan.  It was especially funny since the family was extremely religious and the mother freaked out too, and wouldn't let the kid in the house.  The little bastard always a bit funny after that until they moved away.  If he's reading this, you owe me, pal.  I got you out of the draft.  Buzz-Buzz!

Anyway, that was so much fun I started trying to find out how to get other pheromones.  Like the ones killer bees and fire ants emit when you crush one.  The best I could do was catch a couple of wasps in a jar and then shake the jar and toss it in someone's yard when they were having a barbeque.   Still, there must be a developing market for non-firearm remedies for criminals.  Is there a law against carrying a longbow around the mall?  I doubt it.  Although there IS a law against digging a hole in your back yard.  So all the tiger traps in my back yard are carefully camouflaged.

I have always thought about making 'bear-trap' hands but they are very heavy and 'rat-trap' hands don't seem like practical personal defense tools.  Still, I can't recall any laws against carrying bear traps.  It's not like they are offensive weapons - unless someone mistook a woman's fat ass for two pigs fighting in a Lycra sack.

There really is a GREAT product you can buy, but I'm not going to discuss it because I have some.  It's completely non-toxic, clear, non-staining and easily dispersed - but it will ruin your life for weeks. I'd really have to hate someone to use this on them.