Hmmmm. Are you saying Texans lynched POWs during the Civil War? Or, are you saying that gangs of armed thugs went around to Texas Hill Country farms and ranches murdering women and children?
Neither one would surprise me, but who would want to admit to it!
They lynched German Union loyalists. It is well documented. As far as I know, only men. Germans were also singled out in Missouri and even Kansas as Quantrell wiped out the German colony in his raid on Lawrence Kansas. However, some Germans did serve in the CSA.
As a side note, there was an ulterior motive in German immigration during the eraly 1840's to Texas. The Duke of Saxe-Weimar recently admitted that it was hoped that German immigration would turn Texas into a Germanic state. He brought documents outlining this plan. That was all foiled when Texas joined the Union in 1845.