By Fred Guttenberg and Kevin A. Quinn As the horrific mass shooting in Brooklyn last week reminded us, gun violence has continued to spike across the country over the last three years with no sign of abating. It is clear that we need political leadership to save lives and address this crisis, it will not solve itself. Thankfully for New Jersey, Gov. Phil Murphy has championed common-sense gun violence prevention policies since taking office because he knows this is a preventable public health crisis. Almost a year ago exactly, Gov. Murphy introduced a suite of policies that would directly addr…