Has gun violence decreased in states with open carry laws? I know the laws have not been in effect for long, but I am hoping for some evidence either way. I'm looking for legitimate and unbiased sources.
Gun violence has been declining for the past 30 years. See the Department of Justices Bureau of Statistics for exact statistics. That decline has continued as the number of CCW granting states increased (now 100% of U.S. states). Additionally, violent crime has also been declining over that same time frame.
In answer to the implied question of whether or not CCW laws have decreased crime or gun violence, this is unlikely to be satisfactorily resolved. There are too many confounding variables to ever be able to tease out changes in the gun violence crime rate. A confounding variable is an alternate explanation, that may equally describe the phenomenon, but which precedes or occurs independently of the causal relationship you wish to describe. In other words, there are too many alternate explanations that cannot be controlled for, such as lead in our gasoline made people more violent, and now that there is less lead there is less violence, or more access to abortion decreased the crime rate, or changes in policing towards a "broken windows" approach decreased crime. The list goes on and on. Since all of these things happened at the same time as increased CCW licensing, it is possible that the decrease is due to these things and not CCW licensing.
None of this is to say that CCWs are not decreasing gun violence rates, either, but that it is difficult to prove. I can go into greater depth of the statistical problems, but that would require a longer and more technical answer than I believe you desire.
The answer to your question YES, such crime has decreased.
A general problem in political debate is the use of regression analysis to reduce complex systems down to single variables.
Your question is different from does open carry reduce violent crime?
Here is a study that is on the anti-concealed carry side:
I supply that link as an illustration, not to make a policy point. Both gun rights supporters and gun control advocates sometimes use misleading statistics to make their points.
The reality is that the factors giving rise to violent crime are highly complex.
stats vary in different states and the types of study that is being held. many of the studies have some bias that helps the researcher push towards the side the support which would pull bias data. Theres no way of knowing, but open carry laws aren't brand new, many states have had them. The reduce to gun crime can be due to many factors. I believe the biggest factors of gun related crime decrease are decrease in drug and alcohol use. Also a good percentage of these violent gun related crimes are committed by vets and other people suffering from intellectual disabilities. 25 years ago the Disability Act went into place which helps more people suffering from intellectual disabilities as well as the help for veterans have increased.