"The statute authorizing prosecutions for disorderly conduct, G. L. c. 272, § 53, has been saved from constitutional infirmity by incorporating the definition of 'disorderly' contained in § 250.2(1)" of the Model Penal Code (1980)."

So the law against disorderly conduct in Massachusetts is probably constitutional, because it follows the definition of disorderly conduct in the Model Penal Code...

Model Penal Code s. 250.2: "(1) Disorderly Conduct. Offense Defined. A person is guilty of disorderly conduct if, with purpose to cause public inconvenience, annoyance or alarm, or recklessly creating a risk thereof, he:

"(a) engages in fighting or threatening, or in violent or tumultuous behavior; or

"(b) makes unreasonable noise or offensively coarse utterance, gesture or display, or addresses abusive language to any person present; or

"© creates a hazardous or physically offensive condition by any act which serves no legitimate purpose of the actor.

"'Public' means affecting or likely to affect persons in a place to which the public or a substantial group has access . . . ."

But this language does not appear in the Massachusetts statute under the authority of which disorderly conduct is ordinarily prosecuted in Massachusetts, and a reasonable person might ask how the mere existence of the Model Penal Code can save the Massachusetts statute from "constitutional infirmity."

The relevant Massachusetts statute (G. L. c. 272, § 53) is a relic of the colonial era, and it sounds more like something out of The Old Curiosity Shop than a modern statute...

Section 53. Common night walkers, common street walkers, both male and female, common railers and brawlers, persons who with offensive and disorderly acts or language accost or annoy persons of the opposite sex, lewd, wanton and lascivious persons in speech or behavior, idle and disorderly persons, disturbers of the peace, keepers of noisy and disorderly houses, and persons guilty of indecent exposure may be punished by imprisonment in a jail or house of correction for not more than six months, or by a fine of not more than two hundred dollars, or by both such fine and imprisonment.

This baroque language is either explicated or further confused by a mass of definitions and qualifications in a row of subsections, but...

Faced with this monstrosity, judges in Massachusetts have resorted to the useful fiction that G. L. c. 272, § 53 is a hideously clumsy paraphrase of the Model Penal Code at s. 250.2: (1), which I quoted above, and G. L. c. 272, § 53 has been saved from "constitutional infirmity" by interpretation rather than legislative revision.

In other words, constitutional challenges to G. L. c. 272, § 53 are avoided by de facto adherence to the Model Penal Code s. 250.2: (1).

Now it makes sense to ask if the arrest of Professor Henry Louis Gates Jr. matches the criteria of the Model Penal Code s. 250.2: (1), and it seems to me that the most significant sub-section is 250.2: "(1)(b)...

(b) makes unreasonable noise or offensively coarse utterance, gesture or display, or addresses abusive language to any person present...

If you believe the police report (and this is an essay about matters of law rather than matters of fact), then Professor Gates probably satisfied the criteria of Model Penal Code s. 250.2: (1) by shouting insults at the cop from his front porch, and even though the front porch itself is not a public place, it was sufficiently close to the public sidewalk and street so that "persons in a place to which the public or a substantial group has access" were affected.

That's not the end of the story, and there is never an end to any story involving a charge of disorderly conduct. For example...

Mulvey's conviction was overturned in COMMONWEALTH vs. JOSEPH MULVEY because the location was insufficiently public...

The defendant's mother's property was set back off the road and was surrounded by a variety of different types of fencing. There was a seventy-five to 100 foot long driveway between the road and the house. Entry to the driveway was through a large gate, composed of eight foot high chain link fencing. Green slats had been threaded through the chain link, making it difficult to see through.

The appellate court accordingly overturned Mulvey's conviction, but Professor Gates house is unfenced and adjacent to Ware Street in Cambridge, and the charge of disorderly conduct probably couldn't have been dismissed on the basis of Mulvey, because...

It also is possible that behavior occurring on purely private property may be shown to affect or be likely to affect persons in an adjacent or nearby "place to which the public or a substantial group has access," Model Penal Code § 250.2, such that a disorderly conduct charge would be appropriate.