Does stricter gun control prevent gun violence?

FBI’s uniform crime reports…

California, 3.25 gun murders per 100,000 people. According to the Brady Campaign to Prevent Gun Violence the state with the strongest gun control laws in 2011 is California with a Brady “score” of 81

Texas 2.91 gun murders per 100,000. Brady score 4

In 2011, Utah (the state that the Brady Campaign determined had the least gun control), < 1 (.97) gun murders per 100,000

Washington, D.C., 12 gun murders per 100,000 in 2011. Also, DC is first in gun-related robberies per 100,000 people – with 242.56. In 1976, the District of Columbia required all guns be registered, banned new handguns and required guns at home to be stored and dissembled or locked up. Since the gun ban was struck down, murders in the District have steadily gone down, from 186 in 2008 to 88 in 2012, the lowest number since the law was enacted in 1976. Today, Washington, D.C. still has some of the strictest gun laws in the nation. And yet again, the gun murder rate remains the highest in the US

The WSJ ran an op-ed early this year about the DC gun ban history:

The gun ban had an unintended effect: It emboldened criminals because they knew that law-abiding District residents were unarmed and powerless to defend themselves. Violent crime increased after the law was enacted, with homicides rising to 369 in 1988, from 188 in 1976 when the ban started. By 1993, annual homicides had reached 454.

Everybody I know seems to have an opinion about this.
Does more strict gun control decrease gun violence.
What say you?