Wisconsin is a single-facility detention state with an outsized political and legal footprint. ICE holds detainees at exactly one site — the Dodge Detention Facility in Juneau (Dodge County) — but the state has become a national flashpoint over courthouse arrests (the felony prosecution of Milwaukee Circuit Judge Hannah Dugan), a rapid spread of 287(g) agreements (19 of 72 counties by early 2026), and a Wisconsin Supreme Court original action that could bar all sheriffs from honoring ICE detainers. Federal authorities arrested roughly 1,700 people in Wisconsin since January 2025, with the downtown Milwaukee DHS office the single busiest arrest site.

The Only Detention Facility: Dodge County (Juneau)

• The Dodge Detention Facility (216 W. Center St., Juneau, WI 53039) is Wisconsin’s only ICE detention facility, run by the Dodge County Sheriff’s Office (Sheriff Dale Schmidt) under a long-running IGSA — the partnership is more than 20 years old.
• Important correction to common assumptions: Dodge is NOT GEO-operated and does NOT have a 287(g) agreement. It is a county-run jail holding federal detainees under contract.
• Average daily ICE population ~109 (as of April 28, 2026).
• Dodge deputies also transport detainees to and from the Broadview ICE Processing Center in Illinois, making the jail a node in the Chicago-metro pipeline.
• See facility entry dodge-detention-facility-juneau-wi.

Courthouse Arrests and the Hannah Dugan Prosecution

• April 18, 2025: ICE agents arrived at the Milwaukee County Courthouse to arrest Eduardo Flores-Ruiz. Circuit Judge Hannah Dugan directed him through a side door of her courtroom.
• December 18, 2025: A federal jury found Dugan guilty of a felony count of obstructing federal agents; acquitted on a misdemeanor concealment charge.
• January 3, 2026: Dugan resigned her Wisconsin circuit judgeship in a letter to Gov. Tony Evers.
• February 2026: On appeal, Dugan’s attorneys argue ICE’s administrative warrant gave no authority to arrest inside a courthouse, invoking a common-law privilege against civil arrests at courthouses applied to ICE in four district-court opinions since 2020. A win could bar ICE courthouse operations nationwide.
• ICE has continued the tactic: the Wisconsin Examiner reported a fourth courthouse arrest in Milwaukee by early 2026.
• See county-fight entry milwaukee-county-wi-courthouse-arrests-dugan.

The 287(g) Spread

• By late February 2026, 19 of Wisconsin’s 72 counties had joined 287(g) — up sharply from a handful pre-2025.
• Models: most counties use the Warrant Service Officer model; Kenosha and Marathon use Jail Enforcement; Kewaunee, Sauk, and Waukesha signed up under both models.
• Waukesha County (highest WI heat score) was an early regional leader under retiring Sheriff Eric Severson; all three 2026 sheriff candidates back continuing the program.
• New signers in early 2026: Dunn (signed Feb. 10), Green Lake, Walworth (all Warrant Service Officer). ACLU of Wisconsin condemned new agreements with Washington and Winnebago counties.
• See county-fight entry waukesha-county-wi-287g-leader.

The Voces de la Frontera Detainer Case (Wisconsin Supreme Court)

• ACLU of Wisconsin filed an original action with the Wisconsin Supreme Court in September 2025 on behalf of Voces de la Frontera, arguing that honoring a 48-hour ICE detainer is a new arrest that Wisconsin sheriffs lack statutory authority to make without a judicial warrant.
• Court accepted the case in December 2025. Named defendant sheriffs: Dave Gerber (Walworth), Todd Delain (Brown), Chad Billeb (Marathon), David Zoerner (Kenosha), Chip Meister (Sauk).
• May 18-19, 2026: A federal judge rejected the sheriffs’ bid to remove the case to federal court, sending it back to the Wisconsin Supreme Court — jurisdiction retained. A ruling binding all 72 sheriffs is expected by mid-to-late 2026.
• See county-fight entry dodge-county-wi-ice-detainer-supreme-court (existing).

Notable Enforcement Actions

• Salah Sarsour (April 2026): President of the Islamic Society of Milwaukee (state’s largest mosque), a Palestinian-born lawful permanent resident, was surrounded by ~a dozen ICE agents and detained on “foreign policy threat” grounds. Attorneys and elected officials (Mayor Cavalier Johnson called it “an outrage”) say he was targeted for criticism of Israel. Held at a county jail outside Indianapolis.
• Green card holders: ICE detained an average of 100+ legal permanent residents per month Jan 2025-Feb 2026 in Wisconsin — five times the late-Biden average. A May 2026 case involved a green-card holder detained over a 2014 cannabis conviction after a family trip.
• Milwaukee DHS office: at least 107 arrests Jan-mid-Oct 2025 — the busiest WI site. ~Three-quarters had no pending charges or convictions (vs. 17% statewide), indicating courthouse/check-in collateral arrests.
• Sheboygan Falls mother re-arrested March 2026 after a judge halted her deportation and cleared a green-card path.
• Naqvi defamation suit (April 2026): Sheriff Schmidt sued Sundas Naqvi, Cook County Commissioner Kevin Morrison, and 10 others for $1M each over a disputed claim she was held at Dodge; DHS said she was released from O’Hare secondary inspection within ~90 minutes. See county-fight dodge-county-wi-ice-detainer-supreme-court and facility entry for context.

Sanctuary-Jurisdiction Fights

• Madison and Dane County were placed on a DHS “sanctuary jurisdictions” list in 2026 (later pulled from the DHS site). County Executive Melissa Agard disputed the listing.
• Madison Police issued an updated policy declining 287(g) agreements as inconsistent with its policing philosophy.
• Dane County Sheriff Kalvin Barrett announced the department would stop participating in SCAAP (which shared data with federal authorities).
• DHS publicly pressured Dane County in May 2026 over a detainer on a Nicaraguan man charged with sexual assault of elderly patients.
• See county-fight entry dane-county-wi-sanctuary-fight.

Key Organizations

• Voces de la Frontera — Milwaukee-based immigrant-rights org, lead plaintiff in the Supreme Court detainer case
• ACLU of Wisconsin — litigation and 287(g) tracking
• Islamic Society of Milwaukee — after Sarsour detention
• Wisconsin Watch / Milwaukee NNS — ICE-arrest data reporting

Sources

• Dodge Detention Facility — ICE.gov
• Steady arrests, shifting targets: ICE activity across Wisconsin — Wisconsin Watch (Apr 2026)
• What are 287(g) agreements? Wisconsin sheriff’s departments strengthen cooperation with ICE — Spectrum News 1 (Feb 5 2026)
• Three more Wisconsin county sheriffs agree to work with ICE — Wisconsin Examiner (Feb 28 2026)
• ACLU of Wisconsin condemns new 287(g) agreements (Washington, Winnebago)
• Dugan’s attorneys argue ICE had no right to make courthouse arrest — WPR (Feb 2026)
• Milwaukee judge found guilty on obstruction charge — CBS News (Dec 2025)
• ICE makes fourth courthouse arrest in Milwaukee — Wisconsin Examiner
• Federal judge sends ICE detainer challenge back to Wisconsin Supreme Court — ACLU of Wisconsin (May 18 2026)
• Wisconsin Supreme Court retains jurisdiction over ICE detainer lawsuit — Minnesota Lawyer (May 19 2026)
• Elected leaders and clergy seek release of Salah Sarsour — CNN (Apr 3 2026)
• ICE detains Wisconsin green card holder with 2014 cannabis conviction — Urban Milwaukee (May 24 2026)
• If ICE came to Madison, what would local police do? — Cap Times
• Wisconsin counties concerned over DHS ‘sanctuary jurisdictions’ list — WPR
• Dodge County sheriff files federal lawsuit against woman who claimed ICE detained her — Wisconsin Examiner (Apr 13 2026)