While the number of serious crimes committed in the state has fallen to the lowest number since 2014, the number of cases where the state decided not to prosecute someone who was arrested with probable cause doubled from 595 to 1189 between 2019 and 2021, according to the South Dakota State Crime Reports for those years.
For some number of arrestees to go uncharged is not abnormal. After someone is arrested by police for being suspected of committing a crime, a prosecutor working for the state must decide whether or not to bring criminal charges against them. If the prosecutor decides that there isn’t enough evidence to secure a conviction, they may decide not to bring charges at all.