You could try to do some scripted stuff...
I don?t know, make Barney face the scientist and perform his shooting animation... With a multi_manager you could spawn some blood (env_blood would work?), play the shoot sound and kill the scientist as well... I don?t know if there is any way of spawning decals, maybe naming them and activating them with the multi_manager could work in painting floor and walls in red :P.