What legal authorities allow local police to share data with ICE for identity checks?
Executive summary
Local police share identity-relevant data with ICE under several channels: formal 287(g) deputization agreements that authorize local officers to perform immigration tasks [1] [2] [3]; federal-run information‑sharing systems and programs such as LEISI and legacy systems that route biometrics and driver-license queries between federal and state/local agencies [4] [5]; and legacy fingerprint/booking pipelines like Secure Communities that push fingerprints to ICE for detainer decisions [6]. State statutes and policies can limit or forbid some sharing (California guidance on ALPR and SB 54 noted), but reporting shows routine technical and contractual pathways still let ICE query local data [7] [8] [9].
1. 287(g): deputizing local officers to act like immigration agents
Section 287(g) of the Immigration and Nationality Act lets ICE train and authorize local law enforcement to identify, arrest and detain noncitizens for removal proceedings; the program has expanded rapidly in 2025, covering hundreds of counties and yielding thousands of local–federal agreements that explicitly permit local officers to perform immigration tasks on ICE’s behalf [1] [2] [3]. Those written agreements are a direct legal authority for local officers to collect and pass identity and arrest information to ICE under ICE supervision [2].
2. Federal-led systems and coordination: LEISI and shared databases
DHS designated ICE as a lead for law‑enforcement information sharing and runs the Law Enforcement Information Sharing Initiative (LEISI), which coordinates exchange of biometrics and other identity information across Federal, State, Local, Tribal and Territorial partners [4]. That federal role creates a policy and technical framework by which ICE can access and receive data from non‑federal partners; LEISI is described as the lead facilitator for programs that involve biometrics and information needs across agencies [4].
3. Networked query systems: driver licenses, Nlets and routine queries
Drivers’ license and motor‑vehicle records are routinely shared among state, local and federal agencies via systems such as Nlets (the National Law Enforcement Telecommunications System) and similar networks; reporting shows ICE and DHS components have access and together accounted for large volumes of queries into those systems [5]. This makes driver‑license and vehicle‑related identity data practically accessible to ICE without a case‑by‑case subpoena when the technical access exists [5].
4. Fingerprints and Secure Communities: automatic fingerprint transfers
Secure Communities (S‑Comm) — the fingerprint‑sharing program tied to ICE detainers — routes fingerprints taken during local arrests to federal databases where ICE officers review them for potential detainers and removal action. Advocacy and policy briefs describe this as the mechanism through which local arrest biometrics are “forced” into ICE’s detainer practice [6].
5. Surveillance and vendor channels: ALPR and contractor networks
Automatic license‑plate reader (ALPR) data and camera networks are often administered by private vendors (e.g., vendor platforms used by many cities) and by interjurisdictional sharing; California guidance and reporting show ALPR logs revealing searches done “on behalf of” ICE or by federal units and that state law in California restricts out‑of‑state sharing — yet database access and vendor-sharing practices have allowed ICE and other federal agencies to query local ALPR databases [8] [7] [9]. Those technical pathways can function independent of a single, new warrant or agreement when the local system’s access rules permit it [7].
6. State law limits and conflicting authorities
Some state laws and guidance limit cooperation: California’s Attorney General issued guidance restricting out‑of‑state or federal access to ALPR data and advising how local agencies must log and state search purposes [8] [7] [10]. But reporting from California and other jurisdictions shows those statutory limits do not fully prevent federal queries when local agencies, vendors, or interagency systems remain connected to national networks [8] [9].
7. What reporting does not settle (limitations and open questions)
Available sources document the legal programs and the technical channels ICE uses (287(g), LEISI, Nlets, S‑Comm, ALPR systems) and show widespread use in 2024–2025 [1] [4] [5] [6]. Sources do not provide a comprehensive, clause‑by‑clause catalog of every statutory authority or contract that authorizes each type of data flow in every state; for many local practices, “access occurred” is reported but the exact legal clause or contract authorizing that specific query is not always published in current reporting [8] [7]. Available sources do not mention a complete list of all data types ICE may receive from particular local systems beyond those highlighted (ALPR, fingerprints, driver data) [4] [5] [6].
Bottom line: federal law (287(g), Secure Communities-style fingerprint sharing) plus DHS/ICE-led information initiatives and national telecommunications networks provide the legal and technical authorities for ICE to obtain identity data from local police, while state laws and guidance can constrain but have not fully blocked those channels in practice [1] [4] [5] [6] [8].