We do have one very clear account of someone being killed by a lynch mob, though as with all 'religious' struggles, cultural and social differences were sumsumed under the name of religion.
http://www.smithsonianmag.com/womens-history/hypatia-ancient-alexandrias-great-female-scholar-10942888/?no-ist
Though here of course, there's one difference. The victim was pagan. However, the title of the original post still works. Just remove the last two words and make it 'lynch-mobs-were-early-christians'