Texas Gardening: Volunteer needs identification, 1 by dfwdennis

dfwdennis wrote:
With all of this rain, I've been getting lots of extra volunteers this year. Here's one that popped up behind my shed, and is already about 3 or 4 feet high. It had small pink flowers on it a few days ago, but they now seem to be turning into berries. The longer leaves in the photo are 8 inches long, to give a sense of perspective. I have also spotted a good number of these at various points along the edge of the woods behind my house.

Anyone know what this is? Is it a keeper?

Thanks!
Dennis