Not only that, but everyone, bar pacifist peoples who could only survive if isolated, committed atrocities of one kind or another. Some peoples kept better records of their deeds, others not, or things get lost to time.
That's not to say one can't acknowledge that bad things happened in one's lineage (history), but to think one's lineage is worse than another is oversimplifying things or a case of selection bias, among other things.