"Christ-Killers"

One of the comments on this discussion here reports:

I live in San Antonio, TX. Also, around Easter without fail someone would also call my kids 'christ killers'. When they were little they would come home and want to know who was this 'christ' and why did people think we killed him. They would try and tell them we never killed anyone. We are reform jews and our kids go to temple, etc. My kids weren't bullied, they have friends and enjoy school (well middle school, not so much, but that's middle school). It's the pervasive nature of this that is so upsetting to me. However, my kids also say there are racist slurs directed towards other minorities from mostly hispanic kids, especially african americans, since we have very few.

What in the heck is going on in San Antonio?  Where, oh where, would this terminology be coming from?  I would like to think that any Catholic that would use language like that died before World War II.  Is there something missing from this discussion about San Antonio that I need to know?