United States v. Artis
A Ninth Circuit decision on probable cause for a fugitive-tracking simulator warrant, joint task forces, state execution rules, and derivative searches.
Executive Summary
FBI Special Agent Stonie Carlson, serving on a joint federal-state fugitive task force, sought separate California state search warrants involving fugitives Donnell Artis and Chanta Hopkins. One authorized a forensic search of Artis’s abandoned cellphone for credit-card-fraud evidence. The second authorized 30 days of cell-site simulator use to locate Hopkins through an identified phone. Federal task-force agents used the simulator, identified Hopkins’s San Francisco apartment building, arrested him outside, and developed evidence supporting a later apartment warrant. The Ninth Circuit assumed—without deciding—that the simulator required a warrant. It held the Hopkins warrant valid because the affidavit established probable cause that Hopkins was a fugitive and that he was using the identified phone. A possible violation of California rules governing who may execute state warrants did not invalidate an otherwise valid warrant under the Fourth Amendment. The court separately affirmed suppression from the Artis phone warrant because, after illegally obtained evidence was removed, the affidavit lacked probable cause for the credit-card-fraud search.
Key Holdings at a Glance
Joint Fugitive Investigation
Artis and Hopkins were alleged associates involved in credit-card fraud and identity theft. Both also had outstanding state arrest warrants. Agent Carlson was assigned to a regional fugitive task force operating under the U.S. Marshals Service.
When agents tried to arrest Artis at an Oakland liquor store, he escaped after a scuffle and left his cellphone behind. Carlson retrieved the abandoned phone and later sought a warrant to search its contents. Contacts appearing on that phone helped connect Hopkins to the number later targeted by the simulator warrant.
Two Warrants, Two Different Results
| Warrant | Purpose | Probable-Cause Result | Appellate Outcome |
|---|---|---|---|
| Artis cellphone warrant | Search stored contents for evidence of credit-card fraud | Insufficient after unlawfully obtained apartment evidence was excised | Suppression affirmed |
| Hopkins simulator warrant | Locate a fugitive through a specified phone number | Sufficient—though barely—to link Hopkins to the target phone | Suppression reversed |
The Hopkins Simulator Warrant
The application identified Hopkins as a fugitive with an outstanding state arrest warrant and sought authority to use a simulator to track phone number (832) 763-5555. An Alameda County Superior Court judge authorized use for 30 days and stated that U.S. Marshals Service personnel could assist.
A federal task-force agent deployed the equipment. Simulator information and additional investigation led agents to an apartment building in San Francisco. They arrested Hopkins as he left, found evidence during the search incident to arrest, and used that evidence to obtain a later apartment-search warrant.
Probable Cause for a Fugitive-Tracking Warrant
The Ninth Circuit framed the required showing in two parts:
- Probable cause that Hopkins was a fugitive.
- Probable cause that Hopkins was currently using the specifically identified phone.
No one disputed the fugitive showing. The contested issue was the connection between Hopkins and the phone number.
Connecting Hopkins to the Target Phone
After Carlson recovered Artis’s phone, its locked screen displayed several contacts from the targeted number. A cooperating witness told Carlson that the number belonged to Hopkins and said the information came from Artis, a known Hopkins associate.
The affidavit provided little information about the witness’s general reliability. Still, the contacts appearing on Artis’s phone corroborated the specific tip: it would have been a remarkable coincidence for an invented Hopkins number to appear as an incoming contact on his associate’s phone. The combination was sufficient, although the court described the showing as barely adequate.
Who Executed the State Warrants?
California law directed state search warrants to peace officers and excluded federal agents from that definition, subject to rules permitting assistance. The defendants argued that federal execution rendered both warrants constitutionally invalid.
The Ninth Circuit disagreed. The Fourth Amendment requires a neutral judge, probable cause, and particularity. The identity of the executing law-enforcement officer did not create a greater invasion of privacy or property than execution by a state peace officer would have caused.
Why Federal Rule 41 Did Not Control
Federal Rule of Criminal Procedure 41 applies to searches federal in character. Federal-agent participation is relevant but not conclusive. At the time Carlson sought these warrants, the task force was pursuing state fugitives and state-law offenses, and no federal prosecution was under discussion.
The court therefore assessed the warrants under the Fourth Amendment rather than invalidating them for noncompliance with Rule 41.
Why the Artis Phone Warrant Failed
The Artis warrant sought cellphone evidence of a credit-card-fraud conspiracy. Its strongest supporting fact was that officers had observed counterfeit cards during an earlier entry into Artis’s girlfriend’s apartment. The government did not defend the legality of that entry or the claimed plain-view observation.
Once references to the cards were removed, the affidavit showed mainly that Artis was a fugitive, fled from agents, associated with Hopkins, and was accused by an inadequately supported informant. Those facts did not establish a fair probability that credit-card-fraud evidence would be found on the phone.
Good Faith and Prior Illegal Evidence
The Artis phone warrant was issued partly on evidence obtained through unconstitutional police conduct. After Herring, good faith is not categorically unavailable whenever officers’ own error contributes to a defective warrant; the court must assess deliberateness and culpability.
On this record, the government made no effort to show that the earlier apartment search was lawful or merely isolated negligence. The misconduct was sufficiently deliberate and culpable for exclusion, and the illegally obtained credit-card evidence was decisive to probable cause. Suppression therefore remained appropriate for Artis.
What Artis Does—and Does Not—Decide
- It does not hold categorically that simulator use is a search. The court assumed the point because the government did.
- It does not approve every 30-day simulator warrant. The opinion addressed the challenges presented and noted that Hopkins did not raise execution-scope or particularity arguments.
- It does not excuse state-law compliance. It separates state execution authority from federal constitutional validity.
- It does not permit tracking any phone associated with a fugitive. Probable cause must connect the fugitive to the specifically targeted device.
- It leaves a territorial issue open. Hopkins remained free on remand to renew his argument concerning deployment outside Alameda County.
Agency Operations Checklist
- Confirm current arrest-warrant or offense authority.
- Establish a fresh, documented nexus between the target person and device.
- Identify the phone number and other known identifiers with particularity.
- Describe simulator operation, target and non-target collection, precision, and service effects.
- Define geography, duration, activation limits, and termination conditions.
- Verify territorial authority and who may apply for, execute, or assist with the warrant.
- Coordinate federal-state task-force roles in writing.
- Preserve applications, warrants, returns, logs, settings, locations, results, and deletion certifications.
Litigation and Review Checklist
- Separate application, issuance, and execution defects.
- Determine whether the investigation was state, federal, or joint in character when the warrant was sought.
- Test probable cause for the stated offense and purpose—not a later alternative theory.
- Assess both fugitive status and present use of the target device.
- Review informant basis of knowledge, reliability, freshness, and corroboration.
- Excise illegally obtained facts and reassess the remaining affidavit independently.
- Distinguish statutory execution violations from increased Fourth Amendment intrusion.
- Examine territorial authority, manner of execution, minimization, and derivative warrants.
Frequently Asked Questions
Did the Ninth Circuit hold that simulator use is a search?
No. It assumed, as the government did, that tracking Hopkins’s phone with the simulator required a warrant.
Why was the Hopkins warrant valid?
The affidavit established that Hopkins was a fugitive and, although barely, that he was currently using the specified phone.
Why did the Artis phone warrant fail?
After evidence from an unlawful apartment search was removed, the remaining affidavit lacked probable cause that credit-card-fraud evidence would be found on the phone.
Did federal execution invalidate the state warrants?
No. Even assuming California execution rules were violated, the identity of the federal agents did not itself create a Fourth Amendment violation.
Does Rule 41 always apply when federal agents participate?
No. The search must be federal in character. These warrants furthered state-law fugitive and fraud investigations when issued.
Primary Authorities and Related Law
Published appellate opinion addressing the Artis phone warrant and Hopkins simulator warrant.
Read the complete opinion
Supreme Court decision requiring a warrant for ordinary searches of cellphone contents incident to arrest.
Read Riley v. California
Totality-of-the-circumstances framework for probable cause and informant information.
Read Illinois v. Gates
Objectively reasonable reliance on a later-invalidated warrant.
Read United States v. Leon
Final Assessment
United States v. Artis shows how to build a defensible simulator warrant for a known fugitive: prove the warrant status, prove present use of the specifically identified phone, and obtain express judicial authorization. It also separates constitutional requirements from state warrant-execution rules while insisting that probable cause be tested against the actual purpose asserted.