Party to a Crime in Wisconsin: Aiding, Conspiracy, and Penalties

In Wisconsin, being charged as a party to a crime means the state believes you were “concerned in the commission” of an offense, even if someone else did the physical act. Under Wisconsin Statute 939.05, three kinds of involvement make you a principal in the eyes of the law: directly committing the crime, intentionally aiding and abetting the person who did, or conspiring with others to bring it about. All three carry the same statutory maximum as the underlying offense.¹

One feature of the statute matters before anything else: your liability stands on its own. You can be convicted as a party even if the person who actually pulled the trigger or took the merchandise is acquitted, never charged, or convicted of something different.¹ Prosecutors lean on this because it frees them from having to prove exactly who did what in a group. In a four-person fight, the state does not have to identify whose fist broke the victim’s jaw.

Direct Commission

The simplest route. If you personally performed the criminal act with the required mental state, you committed the crime. Walk into a store, take merchandise, leave without paying, and you directly committed theft. No other party-to-a-crime theory is needed to charge you.¹

Aiding and Abetting

This is the path that surprises people. You do not have to touch a weapon, enter a building, or take a single item. If you intentionally helped someone else commit a crime, Wisconsin treats you as if you committed it yourself.¹

The Wisconsin Supreme Court set out the test in State v. Sharlow. Two things must be true. First, you did something — an act, or even words — that objectively assisted the person committing the crime. Second, you consciously wanted your conduct to provide that help.² Help can look like many things: driving someone to the scene, handing over a tool, standing lookout, or being ready as backup so long as the person committing the crime knows you’re there for that purpose.

You do not need to be physically present. If two people split the tasks a crime requires and each performs their part knowing what the other is doing, both are liable.² Text messages coordinating a plan, supplies dropped off in advance, or scouting a location days earlier can each support an aiding and abetting charge.

Mere Presence Is Not Enough

Being in the wrong place at the wrong time is not itself a crime. Wisconsin’s standard jury instruction states that a bystander or spectator who does nothing to assist is not an aider and abettor.³ The state must show you took some step, however small, to facilitate what happened, and did so intentionally. Watching a fight without intervening, or sitting in a car when someone else makes a drug deal, does not by itself make you a party.

Prosecutors still look at the full picture. If your presence included nodding encouragement, blocking an exit, or sticking around after the plan became obvious, a jury may find you crossed the line.

Conspiracy

The third route is conspiracy: agreeing with at least one other person to commit a crime, or hiring, advising, or recruiting someone else to do it.¹ The agreement does not have to be written, spoken, or spelled out. Courts infer it from behavior — showing up together, dividing roles, moving toward a shared goal.

Wisconsin also has a separate conspiracy statute, Section 939.31, which requires that at least one member take a concrete step beyond planning to advance the scheme.⁴ That step does not have to be illegal on its own. Renting a car, buying supplies, or surveilling a building all qualify. Once someone in the group takes it, the conspiracy is complete.

The Natural and Probable Consequences Doctrine

This is the piece of conspiracy law that catches people off guard. Under Section 939.05(2)(c), a conspirator answers not only for the agreed crime but for any other crime that results from carrying out the plan, if that outcome was foreseeable.¹ The jury asks whether a reasonable person in your position would have known the additional crime was likely given the circumstances.⁵

The classic example: two people plan a robbery, and one shoots the clerk. Even if you never touched the gun and never talked about violence, bringing a weapon to a robbery can make a shooting foreseeable. You could face a homicide charge alongside the shooter. What one conspirator does in carrying out the plan, all conspirators answer for.

Withdrawing from a Conspiracy

Wisconsin gives you a way out, but the door is narrow. Section 939.05(2)(c) says a conspirator can escape liability for crimes committed after withdrawal only if three conditions are met: you genuinely no longer want the crime to happen, you notify every other person involved that you are pulling out, and you do so far enough in advance that the others have a reasonable opportunity to abandon the plan themselves.¹

Quietly walking away does not qualify. You have to affirmatively tell everyone. And even a valid withdrawal only cuts off responsibility for what happens after you leave. It does not erase liability for the conspiracy itself or for crimes already committed before you bowed out.

Penalties Match the Underlying Crime

Every party faces the same statutory maximum as the person who directly committed the offense. The lookout at an armed robbery faces the same Class C felony exposure — up to 40 years in prison and a $100,000 fine — as the person who held the gun.⁶ The full felony range:

Class A felony: life imprisonment
Class B felony: up to 60 years imprisonment
Class C felony: up to 40 years imprisonment, up to $100,000 fine
Class D felony: up to 25 years imprisonment, up to $100,000 fine
Class E felony: up to 15 years imprisonment, up to $50,000 fine
Class F felony: up to 12 years and 6 months imprisonment, up to $25,000 fine
Class G felony: up to 10 years imprisonment, up to $25,000 fine
Class H felony: up to 6 years imprisonment, up to $10,000 fine
Class I felony: up to 3 years and 6 months imprisonment, up to $10,000 fine

Judges have sentencing discretion and may weigh how involved each defendant actually was. A getaway driver often receives less time than the person who committed the violence. But the ceiling is identical, and prosecutors can push for the maximum against all parties when the crime is serious enough.⁶

Restitution Among Co-Defendants

Money consequences run past fines. When a crime causes financial harm, courts order restitution under Section 973.20, and the judge has two options: divide the obligation among defendants based on each person’s share of responsibility, or declare all defendants jointly and severally liable for the full amount.⁷

Joint and several liability means each defendant is on the hook for the whole number, not just a share. If restitution is set at $50,000 and your co-defendant disappears or has nothing, you can be made to pay all of it. The statute does say that when overpayments happen, the court redistributes the excess so each defendant ultimately pays roughly the same proportion.⁷ That is small comfort when you are the one writing the checks while a co-defendant sits in prison without assets. It is one of the most overlooked financial risks of a party-to-a-crime charge.

Harboring or Aiding a Felon Is a Separate Charge

Party-to-a-crime liability is not the same as harboring or aiding a felon under Section 946.47, and the difference is timing. Party liability attaches before or during the crime. Harboring applies afterward — when you help the person who committed it avoid arrest, or you tamper with evidence to derail the prosecution.⁸

Harboring is a Class G felony (up to 10 years, $25,000 fine) if the person you helped committed a Class A through D felony, and a Class I felony (up to 3 years and 6 months, $10,000 fine) for underlying Class E through I felonies.⁸ Lower than what a party faces, but still felonies. Hiding a weapon for a friend, lying to police about someone’s whereabouts, or deleting text messages that hold evidence can all land here rather than under 939.05.

1
Wisconsin State Legislature. Wisconsin Code 939.05 – Parties to Crime
2
Justia Law. State v Sharlow – 1983 – Wisconsin Supreme Court Decisions
3
Wisconsin State Law Library. Wisconsin Jury Instructions Criminal 401 – Party to Crime
4
Wisconsin State Legislature. Wisconsin Code 939.31 – Conspiracy
5
Wisconsin State Law Library. Wisconsin Jury Instructions Criminal 411 – Party to Crime Conspiracy Natural and Probable Consequence
6
Wisconsin State Legislature. Wisconsin Statutes 939.50 – Classification of Felonies
7
Wisconsin State Legislature. Wisconsin Code 973.20 – Restitution
8
Wisconsin State Legislature. Wisconsin Statutes 946.47 – Harboring or Aiding Felons