Source : Webster's Revised Unabridged Dictionary (1913)

Exculpatory \Ex*cul"pa*to*ry\
   Clearing, or tending to clear, from alleged fault or guilt;
   excusing. ``An exculpatory letter.'' --Johnson.

Source : WordNet®

exculpatory
     adj : clearing of guilt or blame [ant: {inculpatory}]