I'm not fully confident in the ID on this one. I couldn't see for sure that there are two equal pads under the tarsal claws
instead of three, but it seems that way. The antennae are 4-segmented, although I'm not sure if the last segment counts as a "segment" rather than a "style" or "arista" sticking off the third segment. It has three ocelli
. The key characteristics generally point to Empididae except "Vein R4+5 usually branched." That vein certainly isn't branched in this specimen, but the key does say "usually."