Unit 6: Statutory Interpretation


  • St. Louis County Ordinances (CP)

  • Tools of Statutory Interpretation (CP)

  • Muscarello (CP)

Key Terms:

  • canons of interpretation (including individual rules)

  • rule of lenity


One of the most important skills to develop as a law student is an ability to read and interpret statutes. Statutory language is often ambiguous, and legal professionals use various interpretive tools to resolve these ambiguities.  These tools include canons of interpretation, which are general rules to consider when arguing about the meaning of a given statute.

The first and most obvious interpretive tool is the grammatical framework of the English language. If a single interpretation stands out as being the most grammatically sensible, then often the interpretive discussion can end there. Similarly, individual words or phrases usually will be interpreted according to their plain language meaning in the context in which they are used. A potential exception to this is an interpretive canon that instructs against reading statutes in a way that leads to absurd results.

Another tool for statutory interpretation is looking to the legislative history behind an act. For example, you might consider interviews, comments, or floor debates in order to get a sense of the intent of individual legislators, legislative committees, or the legislature as a whole. You might also consider the common law preceding a statute, and how the legislative history shows that the statute was either intended to codify the common law, or to differentiate itself from the common law in certain key ways. The cultural climate at the time the act was passed can also be useful in determining legislative intent. Was there strong social opposition to earlier laws, or did they receive public support?

Earlier laws can also be useful because you can look at how they were interpreted by courts. For example, if some of the language in the statute you are trying to interpret is the same or similar to that used in an earlier statute, or in a statute in a different jurisdiction, you can look at how the similar statute was interpreted and use that as a starting point.

Finally, there are the canons of interpretation. One of these canons is the rule of lenity, which states that any ambiguity in a criminal statute should be interpreted favorably for the defendant. Another canon is avoiding interpretations that make words extraneous or unnecessary. As mentioned above, there is a canon that instructs against interpreting statutes in a way that will lead to absurd results. Finally, there is a canon instructing that statutes should not be interpreted in a way that conflicts with other laws.

When engaging in statutory instruction, it is important to remember that the various tools and canons are not black-and-white rules and do not exist in a vacuum. Following one interpretive rule in isolation may lead to an interpretation exactly the opposite of the interpretation that would be reached by following a different rule.  Statutory interpretation is an ambiguous exercise of judgment, persuasion, and plausibility.   It is one of the ways that lawyers make use of their skills.

Consider a hypothetical statute that provides: “It is illegal to take money away from someone without his or her consent.” Suppose that Jerry is in a restaurant, and steals the tip money from a table. Jerry is charged with violation of the statute. The phrase “take money away from someone” is arguably ambiguous, as it is unclear if the money must be taken from someone’s person in order to fall under the statute, or if taking money that is laying about but not the property of the taker is sufficient. If one applied only the rule of lenity, one could conclude that the statute must be interpreted in the former sense, as that is favorable to the defendant. By applying the canon against absurd results, however, one could argue that such a reading of the statute allows people who clearly should be guilty to escape punishment, and thus shouldn’t be allowed. Try to keep in mind the various tools in front of you, and use them as is appropriate for the position you are advocating.

As another example, consider this statute: “It is illegal to injure someone with a firearm.” Jeff is visiting his sister Sarah, and Sarah decides to play a prank on him. She wants to leave an object out so that he will trip over it and fall. Sarah is all out of banana peels, so she decides that her rifle is the next best thing. Sarah makes sure that the rifle is unloaded, and puts it just inside her door, so that when Jeff comes over he will trip and fall. Sarah knows Jeff has catlike reflexes, and doesn’t expect anything bad to come of this. Unfortunately, Jeff is not as agile as Sarah remembers, and he trips over the rifle and subsequently breaks his arm. Sarah is charged with violation of the statute.

If you were Sarah’s defense attorney, you might argue argue that the intent of the legislature was to punish injuries caused by using a firearm as a weapon, not using the firearm as a prank item to make people trip. You could do this by looking to the legislative discussions around the statute. Although that material is not available in this hypothetical, it is likely that senate discussion will revolve around the harm caused by the use of firearms as deadly weapons, and was not intended to apply to unloaded weapons left on the floor. You could also look to certain interpretive canons. If it is unclear whether or not Sarah’s conduct falls under the statute, you could invoke the rule of lenity, arguing that the ambiguity should be resolved in Sarah’s favor.

If you were prosecuting Sarah, you could look to a plain grammatical interpretation to support your position. An ordinary English interpretation says that if Sarah’s conduct injured someone, and if the injury arose from a firearm, then Sarah is guilty. The statute does not on its face distinguish between various uses of firearms that lead to injury.

Both a defense attorney and a prosecutor could argue their position by invoking the canon against absurd results. As a prosecutor, you could argue that interpreting the statute as requiring use of the firearm as firearm leads to an absurd result in this case, as Sarah has clearly met the literal requirements of the statute, and would be escaping guilt on an interpretive technicality. The defense attorney, on the other hand, could argue that the prosecutor’s interpretation would allow guilt even if Sarah had left her gun out accidentally and Jeff had tripped over it. This would be an absurd result, because it would punish Sarah for causing an injury with a firearm only in the most technical sense, in a situation that the legislature most likely had not envisioned.

One of the lessons of the preceding hypothetical is that you should be using the tools of statutory interpretation to make the strongest possible argument for your client.  That means exploiting ambiguities in favor of your interpretation, critiquing alternative interpretations, and tying your interpretation to the purpose behind the law and any broader principles of justice or fairness that might underlie the law.

Questions for Review:

Q1: In Muscarello v. United States, there was a statute at question which punished anyone who “uses or carries a firearm” “during and in relation to” a “drug trafficking crime”. The case revolved around whether the word “carry” included having a gun in the glove department of a car. On what other interpretive grounds could you argue for the defendant? Can further arguments be made on the “carry” point?

Q2: Imagine you are the prosecutor in the Muscarello case. The defense attorney introduces into evidence a quote from the drafter of the statute: “It was always my intent that the word ‘carry’ refer specifically to physically carrying on one’s person. I did not intend for conduct like the defendant’s to be punished.” The defense attorney also calls the court’s attention to a common law rule that preceded the statute. The common law rule applied specifically to carrying on one’s person. How would you as prosecutor overcome this?