Considering the fact that CA and Minnesota have the same rate of mortality and Minnesota has next to no gun laws (you can even walk into a restaurant with your rifle legally) I would say this completely disproves that gun laws have any effect.
I would love for someone to do a study that factors in more points than just number of guns vs gun laws. Maybe like demographics(age,sex,race), drug use, type of drug use, alcohol use, income, religion, political affiliation, ect.
If we're willing to try to pinpoint a common denominator honestly, then we can discuss laws.