It's been that way for decades and generations and is nothing new, for America and D.C.
As to the why that's debated one might argue that white males are most likely to posses/own a gun than any other demographic (another actual fact) and thus with accessibility comes thoughts toward application of as much to end themselves for what ever the reason might be, following a breakdown in mental health status.
But then comes back comparison to other white males from countries opposite to us where firearms are heavily restricted and/or are not, or have not currently (see the UK), been part of the national fabric as in the US.
The results though again wind up comparing out to be same, with countries such as Canada even greater (for males in specific). So once more in the end it's not the gun but the man, and his mentality. Something you, me, and a whole mess of people have been preaching for a very long time now toward crime, criminality, criminal victimization, and firearms in the US.