Search Warrants in Minnesota: Requirements and How to Challenge One

The Core Constitutional Requirements

Under both the U.S. and Minnesota constitutions, a valid search warrant must have:

• A neutral and detached magistrate — the warrant must be issued by a judge, not by the police or prosecutor pursuing the case;
• Probable cause — a sufficient factual showing, made under oath, that evidence of a crime will be found;
• A particular description — the warrant must specifically describe the place to be searched and the persons or things to be seized; and
• Oath or affirmation — the supporting facts must be sworn.

Probable Cause and the "Nexus" Requirement

Probable cause isn't just a belief that someone committed a crime — there must be a "nexus" (connection) between the alleged crime and the specific place to be searched. The affidavit must give the judge a substantial basis to believe evidence will actually be found there. The judge evaluates the affidavit under a "totality of the circumstances" test (from Illinois v. Gates).

Informants and Hearsay

Probable cause can rest on information from informants, even hearsay — but the judge weighs the informant's reliability and basis of knowledge as part of the totality. A named, proven-reliable informant carries more weight than an anonymous tip, and police corroboration of the tip strengthens it.

Information Can't Be "Stale"

Probable cause must be current. If the facts in the affidavit are too old, the warrant can be challenged for staleness — the likelihood that evidence is still present may have evaporated. How much time is too much depends on the nature of the crime and the evidence (ongoing drug operations differ from a single past event).

Particularity: No "General" Searches

The warrant must specifically describe what's being searched and seized — police can't get a blanket license to rummage. A warrant that's too broad or vague can be challenged. The scope of the search is limited to places where the described items could reasonably be found.

Anticipatory Warrants

Some warrants are "anticipatory" — they authorize a search that becomes valid only after a future "triggering event" (for example, the delivery of a package known to contain contraband). These are permitted, but the affidavit must show probable cause that the triggering event will occur and that evidence will then be found.

Challenging a False or Misleading Affidavit (a "Franks" Challenge)

This is one of the most important warrant challenges. Under Franks v. Delaware, if an officer included a deliberate falsehood or acted with reckless disregard for the truth in the affidavit — or omitted material facts — you can challenge the warrant. If the false statement was necessary to the probable-cause finding, the warrant can be invalidated and the evidence suppressed. This requires a substantial preliminary showing to earn a hearing, but it can be decisive.

Seizing Items Not Named in the Warrant

Police executing a valid warrant can sometimes seize items not listed in it — but generally only under the plain-view doctrine: the officers must be lawfully present, the item's incriminating nature must be immediately apparent, and they must have lawful access to it. They can't use the warrant as a pretext to search for unrelated things.

A Newer Minnesota Limit: The Smell of Cannabis

Since Minnesota legalized adult-use cannabis, state law now provides that the odor of cannabis alone does not create probable cause to search a person, vehicle, or place. This is a meaningful change — the "I smelled marijuana" justification that once supported countless searches no longer stands on its own. (See our cannabis page for more.)

Execution, Return, and Filing

A warrant must be executed within the time the law allows and generally during authorized hours (special rules apply to nighttime and no-knock entries — see our separate page). After the search, officers must leave a copy of the warrant and a receipt/inventory of what was seized, and file a return with the court. Defects in execution can sometimes support a challenge, though not every technical violation requires suppression.

How Warrants Get Challenged — Summary

• No probable cause / no nexus to the place searched;
• Stale information in the affidavit;
• Lack of particularity — overbroad or vague;
• False or misleading affidavit (a Franks challenge);
• Unreliable informant information without corroboration;
• Seizure beyond the warrant's scope;
• Defective issuance (not truly neutral magistrate) or execution.

If a warrant or its execution violated these rules, the remedy is often a motion to suppress the evidence — which can gut the prosecution's case.

Key Terms

• Probable cause: A substantial factual basis to believe evidence of a crime will be found.
• Nexus: The required connection between the crime and the place to be searched.
• Particularity: The requirement to specifically describe the place and items.
• Franks challenge: A challenge based on a false or reckless affidavit.
• Staleness: When affidavit information is too old to support probable cause.