I'm not sure if this occurred after the murder, but their performance of "Sympathy for the Devil" at Altamont is phenomenal.
Actually, I can tell you that "Sympathy for the Devil" came before the murder. After it (and to repeat, there is no reason to believe the Stones knew about it at the time) the setlist went:
Brown Sugar/ Midnight Rambler (!)/ Live With Me/ Gimme Shelter/ Little Queenie/ Satisfaction/ Honky Tonk Women/ Street Fighting Man
--each more incredible than the last. Greil Marcus (who was there) hypothesizes that on some unconscious, telepathic level, they agreed that to get out of there alive they just had to be so fucking great that when they left the stage, everyone would just...Move Back.