Immigration mandatory detention is a particularly harsh example of the structural violence embedded in immigration enforcement. It deprives liberty without bond for immigrants with prior crimes, and assigns many individuals to the harsh conditions associated with unnecessary and even wrongful detention. Mandatory detention has been justified on the grounds that mandatory detainees are a danger to public safety. This article puts to the test this presumption of dangerousness among mandatory detainees, and finds, to the contrary, that immigrants with prior charges or convictions are no more dangerous than any other category of individuals in Immigration and Customs Enforcement (ICE) custody. Using the risk classification assessment (RCA) tool, which the author is the first to obtain through the Freedom of Information Act, the article contributes to the growing criticism of mandatory detention, providing evidence that many of those in mandatory detention should probably have never been detained.