Immigration and Customs Enforcement. ICE collects data on every person it encounters, arrests, detains, transports via flight, and deports. We post below data that ICE produced in response to several FOIA requests by multiple organizations. Crucially, in some data releases, there are linked identifiers across data types such as arrests and detainers, allowing merges that enable tracing immigrants’ pathways (anonymously) through the immigration enforcement pipeline. The identifiers are, unfortunately, different across releases, only enabling merging within a data release. See below for a description of each release. Our ICE codebook describes each data table and the fields within them.