How not to cache weapons

I would love to know the backstory - was this a sellers drop for someone to pick up? From the London Daily Mail:

Walker finds two guns in a violin case along Potomac River in Washington D.C. - leading cops to locate even more weapons nearby
A number of weapons, including two guns in a violin case, have been found stashed along the Potomac River in Washington D.C.

U.S. Park Police said a woman walking in the woods near the C&O Canal, which runs along the river, found the case on Wednesday.

When police arrived they found more guns and ammunition stashed in pails and garbage bags nearby.

And where they were found?

'Nobody ever hikes on that side of the canal' where the violin case was found, Saffir said. 'People walk on the towpath.'

She added that the area is 'normally super quiet.'

D.C. has draconian gun laws - Dick Heller was a security guard and was licensed to carry firearms at work. He wanted to have a gun for his home protection but the D.C. authorities said no. He took it all the way to the Supreme Court and won. More: District of Columbia v. Heller

Why would someone be stashing that quantity of weapons - were they planning something for the inauguration? Our friends the Amish Muslims? A bit of a pity they didn't just hang back and see who came to retrieve them...