Security for D.C.

The House is set to lift the D.C. Gun Ban?

Will the Senate go along? it will be interesting to see.
Here's a question for you though. . . .

Will it take an act of Congress to undoe the D.C. Gun Ban?
Since all of D.C. is under the Jurisdiction of the Department of Interior and treated, in some respects, as a giant National Park, could the Secretary of Interior decree through regulatory edict that guns are allowed?