Want to reduce crime?

Then take a look at this document, Minnesota's description of who commits crimes, upon whom they commit them, and what the likely motivations are. 

For example, with the crime of murder, most analyses go simply to page 17 and note that about 3/4 of murders are committed with a firearm, and the vast majority of those are committed with a handgun.

On the other hand, we can go to Figure 7, where the situation of the murder is given.  In this case, 21 result from domestic/lovers' quarrels, 16 are the result of gang activity, 19 result from other criminal activity, 19 are the result of another argument, and 12 have unknown causes. 

In short, if you don't want to be on either side of a murder in Minnesota, your best bet is to avoid gangs, criminals, and take care of your family relationships well.   Get rid of guns, and you might simply replace gun murders with knife and blunt instrument murders, really. 

Now I would guess that the drastic drop in murder rates since 1994 has something to do with a very simple factor; we are putting criminals in jail and keeping them there longer, really until many of them no longer have the "vim and vigor" needed to be a "competitive thug."  If we want it to drop further, we need to continue this and figure out what government can do to reduce family breakdown.

Oh, and it should be said; the drop in murder rates probably also has something to do with the fact that criminals can increasingly expect their victims to shoot back at them.  Like it or not, the increase in carry permits and guns out there since 1994 corresponds nicely with the drop in murder rates.