The substantial step test is the standard most American courts use to decide whether a defendant’s conduct has crossed from preparation into a criminal attempt. Drawn from Model Penal Code Section 5.01(1)(c), it asks whether the person has already taken an action significant enough, and strongly corroborative enough of criminal purpose, to count as attempting the crime, judged under the circumstances as the defendant believed them to be.1United States District Court for the District of Massachusetts. Pattern Jury Instructions – Attempt The focus is backward-looking: not how close you came to finishing, but what you have already done.
What Counts as a Substantial Step
The Model Penal Code doesn’t leave the term floating. Section 5.01(2) lists specific categories of conduct that a court cannot dismiss as mere preparation, so long as the behavior is strongly corroborative of the defendant’s criminal purpose.
- Lying in wait for the victim, or following them.
- Enticing or luring the victim to the place where the crime is to occur.
- Scouting or reconnoitering the location of the planned crime.
- Unlawful entry into the structure, vehicle, or enclosure where the crime is intended.
- Possessing materials specially designed for the crime, or that serve no lawful purpose under the circumstances.
- Collecting or fabricating materials at or near the place of the crime.
- Soliciting an innocent agent to engage in conduct that would constitute part of the offense.
State v. Lammers shows how the categories operate in a real case. The court there held that purchasing assault rifles and engaging in target practice constituted a substantial step toward attempted first-degree assault, because those acts advanced the defendant’s plan and strongly indicated criminal intent. The defendant hadn’t reached the scene or confronted anyone, but the preparation was concrete, specific, and tied to a plan of violence. That is the shape of the inquiry: concrete action pointing unmistakably at a particular crime.
The Corroboration Requirement
A substantial step isn’t just a big step. It has to be strongly corroborative of the defendant’s criminal purpose. This is the test’s built-in safeguard. Your actions, viewed from outside, must make the illegal objective unmistakable. If the same conduct is equally consistent with an innocent motive, the standard is not met.
Someone found with lockpicks in a car outside a jewelry store at 2 a.m. is in a very different posture from someone with the same tools in a hardware-store parking lot at noon. The tools are identical; the surrounding facts aren’t. Courts and juries look at the full context — text messages setting out a plan, surveillance footage of repeat visits to a target, searches for information on a specific security system, recorded conversations about the intended offense. When the physical acts and the surrounding evidence line up behind a specific criminal objective, corroboration is satisfied. When they don’t, the conduct stays on the preparation side of the line.
How the Test Replaced the Dangerous-Proximity Rule
Before the Model Penal Code, most jurisdictions used a common-law standard that asked how close the defendant had come to completing the crime. Under this dangerous-proximity test, attempt liability attached only when the actions had advanced to the point where the offense would almost certainly have occurred without outside interference.
A 1927 New York case is the standard illustration. Four men planned to rob a payroll carrier. They armed themselves and drove to several locations where they expected to find the victim, and they were arrested before locating him. The court reversed the attempt conviction because the defendants had never gotten close enough to the robbery itself. Under dangerous proximity, that was preparation.
The practical problem was obvious. Police often had to wait until a crime was nearly complete before they could intervene, which left victims exposed and gave officers little room to act on credible intelligence. The substantial step test shifted the inquiry. Instead of measuring the distance still to be traveled, it looks at what the defendant has already accomplished. If those acts are significant and strongly corroborative of criminal purpose, the line has been crossed, and arrest can happen earlier.
Intent Still Has to Be Proven
The substantial step test governs the act side of attempt. It doesn’t replace the mental-state requirement. Every attempt prosecution still has to prove that the defendant specifically intended to commit the underlying crime. That is a higher bar than general criminal intent. Attempted murder requires proof that the defendant actually wanted the victim dead; reckless or generally hostile behavior isn’t enough. Someone who fires a gun into a crowd may face serious charges, but an attempt conviction requires proof that they aimed at a particular result.
This filters out negligent and reckless conduct entirely. A driver who nearly hits a pedestrian never intended to kill anyone, so attempt doesn’t fit, however frightening the near-miss was. Courts look at the defendant’s subjective goal. Did the person set out to accomplish every element of the crime? If not, attempt liability doesn’t attach, even where the conduct caused harm.
Because attempt is a specific-intent crime, severe voluntary intoxication can sometimes figure into the defense. Where that defense is available, it doesn’t guarantee acquittal, but it can reduce the charges to an offense requiring only general intent. Courts treat the defense narrowly, and the burden typically sits with the defendant.
Impossibility and the “As the Defendant Believed Them to Be” Clause
The substantial step test judges conduct under the circumstances as the defendant believed them to be. That phrasing matters when the crime turns out to be impossible to complete.
Factual impossibility is not a defense. A pickpocket who reaches into an empty pocket, or a buyer who takes delivery of goods they believe are stolen but which are not, has done everything they intended to do; the plan failed because reality didn’t match the belief. Courts universally reject factual impossibility.2Oklahoma Court of Criminal Appeals. Impossibility Unavailable as a Defense The Model Penal Code reinforces that result through its “as the defendant believed” language.
Legal impossibility is different. If a person completes every act they intended but the conduct doesn’t actually violate any law, there is no underlying offense to attempt. The textbook example is “bribing” someone the defendant believes to be a juror but who in fact is not.2Oklahoma Court of Criminal Appeals. Impossibility Unavailable as a Defense In jurisdictions that follow the Model Penal Code, courts have largely collapsed the old distinction between the two kinds of impossibility, because the test anchors liability to the defendant’s view of the facts.
Walking Away After a Substantial Step
What happens if you take a substantial step and then stop? Under the Model Penal Code, voluntary abandonment is an affirmative defense, and roughly half of American jurisdictions have adopted some version of it. Where it is recognized, a successful claim results in acquittal.
The requirements are strict. The decision to stop has to be both voluntary and complete.
- Voluntary means a genuine change of heart, not quitting because a police car appeared, the target had better security than expected, or the risk of getting caught went up. Outside pressure that makes the crime harder doesn’t count.
- Complete means giving up the criminal objective, not postponing it or switching targets. Waiting for a better opportunity isn’t renunciation.
Where the defense isn’t available, the common-law rule applies: once your conduct has satisfied the substantial step test, stopping voluntarily won’t prevent conviction, though it may influence sentencing. Jurisdiction matters here, and it’s worth checking which rule applies before relying on the idea that walking away undoes an attempt.