An Etymological Dictionary of the German Language/Annotated/Schuld
Schuld, feminine, ‘debt, crime, guilt,’ from Middle High German schult (d) and schulde. Old High German sculd, sculda, feminine, ‘obligation, debt, culpability, sin’; compare Old Saxon sculd, feminine, ‘debt, culpability, sin’; Anglo-Saxon sčyld, ‘guilt, sin.’ An old verbal abstract from the root skal, which appears also in Lithuanian skolà, ‘guilt,’ skìlti, ‘to get into debt,’ and skelěti, ‘to be indebted,’ as well as in Prussian skallisnan, ‘duty’; Latin scelus does not appear to be connected with it.