They also are foul smelling unlike the elderberry
the berrys on these are much bigger however ... I actually ate some as a kid ... puked a lot I did ... What you are calling red elderberries is the poke berry, notice this description

Avoid elderberries species with red fruit growing in rounded, instead of flat clusters. They may make you sick. Herculesí club is a shrub or small tree with feather-compound leaves that looks a little like the common elderberry. It has flat clusters of poisonous, black berries, often arranged in a ring, and a short, unbranched, thorny trunk. Elderberries are thornless.



poke berry

here is the common elderberry, notice the umbrella shape ... notice too the berries are very dark purple like a concord grape.

common elderberry

Now if you see the umbrella shape (no thorny branch) and they are red you most certainly can eat them ... they are just elderberries that are not fully ripe, they have great vitc but are bitter in taste ..I have eaten them even green in survival ... you will not get sick on an elderberry bush.