ICE detention holds after release from criminal custody may be lodged for 48 hours, excluding weekends and holidays. 8 C.F.R. 287.7(d). There does not seem to be any legal or regulatory basis for "investigatory" holds. When counsel objects to such a hold, and demands to know the authority for such a hold, practitioners report ICE releases the client immediately.
The statutory basis for a detainer seems to be restricted to people arrested for a violation of any law relating to controlled substances. INA 287(d) provides:
In the case of an alien who is arrested by a Federal, State, or local law enforcement official for a violation of any law relating to controlled substances, if the official (or another official)--
(1)--has reason to believe that the alien may not have been lawfully admitted to the United States or otherwise is not lawfully present in the United States,
(2)--expeditiously informs an appropriate officer or employee of the Service authorized and designated by the Attorney General of the arrest and of facts concerning the status of the aliens, and
(3)-- requests the Service to determine promptly whether or not to issue a detainer to detain the alien, the officer or employee of the Service shall promptly determine whether or not to issue such a detainer. If such a detainer is issued and the alien is not otherwise detained by Federal, State, or local officials, the Attorney General shall effectively and expeditiously take custody of the alien.>
If a noncitizen is held past the 48 hours, or is held on the basis of an illegal "investigatory" hold, s/he can sue the custodial facility for false imprisonment.
8 C.F.R. 287.7(a) refers to the purpose of the detainer being ICE seeking custody to "arrest and remove" because immediate custody by ICE is impracticable. That appears to essentially require an NTA or ICE warrant of arrest as a basis for the detainer, i.e., just like any other detainer from counties or states based on an outstanding warrant. In practice, however, the detainer precedes issuance of an NTA or Warrant of Arrest.
8 C.F.R. 287.7(b) lists officers able to issue a detainer. 8 C.F.R. 287.7(b)(8) includes any other immigration officer needing authority to issue a detainer under INA 287(d)(3), who is given the authority to issue a detainer. This seems to imply that the statutory authority for a detainer flows from INA 287(d), which is limited to noncitizens arrested for controlled substance violations.
8 C.F.R. 287.7(c) requires that state and local law enforcement provide records necessary to determine if issuing detainer/NTA is appropriate. It states "the criminal justice agency requesting such action (issuing detainer) shall" provide said records. That is, authority flows from INA 287(d) that a detainer only issues when requested by the state or local agency under INA 287(d) - not that ICE decides to issue a detainer absent a request. 8 C.F.R. 287.7(d) then allows issuance of the detainer, after a determination by ICE (based on a request from a state and local agency under INA 287(d).
8 CFR 287.7 is also explicitly titled - "Detainer Provisions under Section 287(d)(3) of the Act" - which limits it to controlled substances arrests.
In some areas, persons are routinely held on detainers for non-controlled substance charges. After a person has been arrested, if the charge is a felony, state law required inquiry at booking into place of birth. Most jails make the inquiry for misdemeanors also (especially if the arrestee has a Hispanic name). Some jails then notify ICE about any arrest of a person born abroad, other jails do so only for those arrested on felony charges. Then, the ICE office interviews the person in person or by phone. If the person admits to ICE that they were born abroad, or entered EWI, then a detainer is faxed to the jail. ICE then picks person up after 48 hours after the person has been released from state criminal custody, and the person is interviewed in person by an ICE officer who draws up the NTA and I-213.
INA 236(a) states: "on a warrant issued by the Attorney General, an alien may be arrested and detained." INA 236(d) limits the 24-hour basis to identify "criminal aliens" to those charged with aggravated felonies, except that under INA 236(d)(3), DHS may also help the state courts identify "aliens pending prosecution" if the governor requests it.
More immigrants might be released from state custody without an NTA if ICE was actually required to draw up and serve the NTA and Warrant of Arrest, rather than merely faxing Form I-247 to the jail.
The misuse of detainers has been challenged in the Tenth Circuit, which held that the detainer is nothing more than a piece of paper and does not establish custody warranting a habeas action for unconstitutional detention by federal authorities. If a detainer does not establish federal custody, and yet the person remains detained, then the state must be the custodian. This question has been left unresolved by the Tenth Circuit. In Colorado, criminal judges will sometimes refuse to give bonds to individuals with ICE holds, finding (however illogically) that the hold makes the individual an increased flight risk. In other cases, people are refused admission to halfway houses or bootcamp because of ICE holds, and end up serving hard time on cases despite a plea agreement to treatment in a halfway house. The ICE detainer also automatically disqualifies detainees from parole even if they have an otherwise spotless record. One person served three weeks in jail on a domestic violence sentence, and then spent an additional three months in jail waiting for ICE to pick her up.
Thanks to Jonathan Moore.