evidence: The dismissals represent a small fraction of the hundreds of federal and state child pornography prosecutions since 2011. More often, defendants plead guilty in exchange for a reduced sentence. (Of 17 closed cases brought since 2017 by the U.S. attorney’s office in Los Angeles, all but two resulted in plea deals, ProPublica found.) Even after their charges were dropped, Tolworthy and Hartman are both facing new trials. Still, the dismissals are noteworthy because challenges to the software are spreading among the defense bar and gaining credence with judges.