889 F.3d 418
7th Cir.2018Background
- Federal agents obtained a July 2015 warrant authorizing pen registers, trap-and-trace devices, historical cell-call records, and “electronic investigative techniques” to locate two target cell phones.
- The warrant specifically authorized the use of a cell-site simulator (an IMSI-catcher) to capture and analyze signals emitted by the Subject Phones.
- DOJ policy stated its simulators identify target devices, collect only signaling/location metadata (not content), and are configured as pen registers (no content interception).
- The agents did not seek a wiretap warrant and did not claim to capture call contents or personal data requiring wiretap authorization.
- Sanchez-Jara moved to suppress the location/traffic data; the district court denied suppression. He entered a conditional guilty plea reserving the right to challenge the warrant and appealed.
- The district judge’s warrant recited both § 2703(d) “reasonable grounds” language and explicitly found probable cause; the court evaluated validity under the Fourth Amendment accordingly.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether a § 2703(d) warrant that uses "reasonable grounds" satisfies the Fourth Amendment's probable-cause requirement | Sanchez-Jara: "reasonable grounds" is less than probable cause, so warrant insufficient under the Fourth Amendment | Government: "reasonable grounds" is equivalent to probable cause, and here the warrant also expressly found probable cause | Warrant valid: district judge expressly found probable cause; presumption of correctness applies; warrant suffices |
| Whether use of a cell-site simulator without a wiretap warrant violated Fourth Amendment by obtaining contents or other data | Sanchez-Jara: implied concern that simulator could be used broadly to capture content or personal data | Government: DOJ policy/configuration prevented collection of call contents or phone data; only metadata/location was sought | No record that agents obtained content; warrant limited to metadata/location; wiretap statute not implicated |
| Whether the warrant was an unconstitutional general warrant (lack of particularity) | Sanchez-Jara: warrant authorized general search and following phones anywhere, thus overly broad | Government: warrant targeted identified phones and described the evidence/technique (tracking location/traffic) | Particularity satisfied: tracking identified phones is analogous to GPS tracking; not an open-ended rummaging warrant |
| Whether evidence discovered after using the simulator contaminated later consents and seizures | Sanchez-Jara: suppression sought to exclude derivative evidence | Government: warrant supported by probable cause; no illegal search occurred | Evidence admissible: discoveries did not taint later consents; conviction affirmed |
Key Cases Cited
- United States v. Patrick, 842 F.3d 540 (7th Cir. 2016) (related precedent on cell-site simulator use)
- Illinois v. Gates, 462 U.S. 213 (1983) (probable cause defined by the totality-of-the-circumstances standard)
- United States v. McIntire, 516 F.3d 576 (7th Cir. 2008) (judicial probable-cause findings carry a strong presumption of correctness)
- Warden v. Hayden, 387 U.S. 294 (1967) (rejecting the "mere evidence" doctrine)
- Andresen v. Maryland, 427 U.S. 463 (1976) (Fourth Amendment particularity requirement for warrants)
- United States v. Jones, 565 U.S. 400 (2012) (GPS tracking and Fourth Amendment implications)