ICE (U.S. Immigration and Customs Enforcement) is the Department of Homeland Security agency that enforces federal immigration laws inside the U.S.; its principal enforcement arm, Enforcement and Removal Operations (ERO), identifies, arrests, detains, and removes noncitizens. ICE officers derive arrest and detention authority from federal immigration statutes—most notably 8 U.S.C. §1357 (powers to question, arrest, search and seize) and statutes governing immigration detention (e.g., 8 U.S.C. §§1226 and 1231)—and from implementing regulations and DOJ/ICE policy.
In DHS/ICE usage, “criminal illegal alien” refers to a noncitizen who is removable/unauthorized in the U.S. and who has been charged with or convicted of criminal offenses. Criminal prosecution for crimes is handled by state or federal courts regardless of immigration status; separately, immigration law treats certain crimes as grounds for inadmissibility or deportability (see 8 U.S.C. §§1182 and 1227) and can trigger detention and removal proceedings before immigration courts.
WOW.DHS.gov (“Worst of the Worst”) is a public DHS/DHS–ICE web collection that lists noncitizens ICE describes as serious public-safety threats; it provides names, country of origin, convictions/offenses, and arrest locations and allows filtering/search by country and state.
The 70% claim is an ICE statistic that ICE has repeatedly used in press releases and its ERO statistics: ICE reports that roughly 70% (or more) of noncitizens it arrests have criminal convictions or pending criminal charges, but the precise percentage can vary by operation and fiscal period and is presented by ICE on its statistics and press-release pages rather than as a single peer‑reviewed dataset.
The “more than 1,300% increase in assaults” phrase appears in the DHS/ICE statement but the release does not cite a public dataset or explicit timeframe; I could not find a DHS/ICE page that documents the underlying data or period for that percent increase in a public report.
After ICE arrests a noncitizen with prior convictions, common next steps include: (1) custody in ICE detention (civil immigration custody) under statutes such as 8 U.S.C. §§1226/1231; (2) if still subject to state/federal criminal charges, continued criminal prosecution in the courts; and (3) initiation or continuation of immigration removal proceedings before an immigration judge (EOIR), often culminating in removal (deportation) if no relief is granted. Criminal prosecution and immigration processes can proceed concurrently.
ICE coordinates with local law enforcement and federal prosecutors through formal mechanisms (e.g., information-sharing, detainers, Criminal Alien Program, 287(g) agreements) and by referring cases to U.S. Attorneys when federal crimes are involved; ICE also works with state/local agencies to transfer custody so criminal prosecutions can proceed and then assume immigration custody for removal proceedings.