I found a tree in my neighborhood, all of its leaves had turned bright red. I'm no expert, but I have a Audubon Society 'Trees of North America (western edition)'. The leaves and bark match the description of the western soapberry but there are no berries on the tree or on the ground. (There are a lot of acorns under the nearby oaks.) The book says they hold on to their berries during the winter.
I don't have a camera (no, not a 'smart'phone either) so I'm just asking whether a soapberry can lack berries and whether its leaves can turn red. I see these trees often around town, now that I've begun to look; none of them have berries. None of them are as red as this one, even on the same block.
Curiously, the median of this street has trees with ID tags. There's a 'soapberry' tag on a Chisos Red Oak
