What procedures should jails follow to lawfully respond to an ICE detainer while minimizing litigation risk?
Executive summary
Local jails must treat ICE detainers as nonbinding requests and avoid relying on them as independent legal authority to continue holding someone beyond the time they otherwise would be released, because courts and guidance have repeatedly found detainers lack the force of a warrant and can create Fourth Amendment liability for unlawful detention [1] [2] [3]. To minimize litigation risk, jails should adopt clear written policies that tie any hold to valid state law authority or a judicial warrant, verify probable cause behind ICE requests, limit information-sharing to what state law permits, and maintain meticulous records and staff training to demonstrate lawful practices [4] [5] [6].
1. Know the legal baseline: detainers are requests, not warrants
Federal detainers request that local agencies "maintain custody" up to 48 hours but do not themselves authorize continued detention; multiple federal courts and commentators have held compliance is not mandatory and that jails remain liable if they detain someone without independent probable cause or statutory authority [4] [2] [3]. State law can add constraints—some states and counties expressly prohibit holding someone beyond release solely on an ICE detainer—so local officials must read state statutes and case law before acting on any request [7] [8].
2. Adopt a written policy that sets clear guardrails
A defensible policy should state that detention will only occur when there is express state statutory authority, a judicial warrant, a valid 287(g) delegation, or other lawful basis, and otherwise will treat ICE communications as a Request for Notification rather than an automatic hold; sanctuary-policy templates and national overviews explain these distinctions and note jurisdictions legitimately narrow cooperation to serious offenses to protect public safety and limit liability [6] [2] [9].
3. Verify probable cause and require credible documentation from ICE
Before any extended custody, jails should demand contemporaneous, signed documentation from ICE establishing probable cause of removability or a judicial warrant and should not accept database checks or automated notifications alone—ICE has conceded in litigation that database evidence or birth-country indicators without corroboration are insufficient to show probable cause [5] [10] [11].
4. Operational steps on receipt: time limits, notifications, and custody transfers
When an ICE request arrives, staff should determine the inmate’s anticipated release time under state law; treat the detainer as a nonbinding request unless accompanied by a warrant or 287(g) authority; if accepting notification-only requests, provide ICE with release timing but not retain custody beyond legal release; and if transferring custody, document ICE officers’ identity, authority, and time of transfer to reduce later disputes—these practices mirror guidance from immigration legal advocates and court rulings emphasizing clarity around who has lawful authority to detain [1] [4] [11].
5. Records, transparency, and staff training to avoid litigation traps
Document every ICE contact, the specific legal basis relied upon for any continued custody decision, and the inmate’s release timeline; train intake and supervisory staff to distinguish between notification requests and detention requests, and to recognize that erroneous detainers have led to costly settlements and jury findings against counties—examples include multiple settlements and jury verdicts in Minnesota and elsewhere tied to unlawful post-release holds [8] [12] [13].
6. When to refuse: balancing public safety, state law, and liability
Refusal to honor detainers is legally permissible in many jurisdictions and can reduce constitutional exposure, particularly where detainers lack probable cause or state law forbids extended holds; however, refusal can carry political pushback and federal pressure, so jurisdictions should ground refusal in written legal analysis and public-safety reasoning [1] [6] [14]. Conversely, complying without independent authority risks Fourth Amendment claims and civil liability even where ICE represents public-safety interests [3] [2].
Conclusion: standardize, verify, document, and train
The practical path to minimizing litigation risk is straightforward in theory: adopt written policies that treat ICE detainers as requests, require judicial or statutory authority (or credible ICE documentation) before any additional detention, limit information-sharing to what law allows, and document and train rigorously so the agency can show every decision was tethered to lawful authority rather than deference to a federal request—these measures reflect lessons from litigation, settlements, and national guidance and keep custody decisions defensible in court [9] [5] [2].