Legally, you may sue him for damages or compensation--being in prison or convicted does not discharge his other potential civil liability (whether to you or to anyone else he injured or whom he owes money). Practically, if he's in prison and not working, and may have spent all or most of his own money/assets on his crimimal defense--or was someone who never had much income or assets--then there may be no point to suing: even if you won, you would likely not recover anything.