"Deadly nightshade" is one of those common names applied to multiple species (including this one) but usually applied to belladonna. I prefer "bittersweet nightshade" for this one because that's a more or less literal translation of the scientific name.

Bittersweet apparently refers to the taste of the twigs, which were used medicinally at one time. Like tomatoes and potatoes, the greens and stems are toxic, as well as the unripe berries. There is great caution around the ripe berries, but that may be unwarranted.