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“Les Macquereaux,” the Campbell Law, and Human Trafficking in Early Denver

March 2023

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Around the turn of the 20th century, a French gang called “Les Macquereaux” became active in Denver. The gang was known for importing women into the United States from France and from other countries for forced prostitution. It was also accused of enticing or forcing Colorado women and girls into becoming prostitutes.

Les Macquereaux had chapters in several large US cities. Women who fell under the gang’s power were often forced to work as prostitutes until they had bought their way out of bondage.1 In Denver alone, Les Macquereaux included an estimated 75 men who lived off the earnings of prostitutes.2 The gang even owned a ranch near Sheridan, Colorado, where its members could seek refuge during periodic law enforcement sweeps.3

The word “maquereau” (without the added “c”) had long been used to refer to a pimp in French slang.4 But as an organized gang, “Les Macquereaux” took pimping to a new level, taking on the trappings of a secret order or cult. Like many gangs, it went by more than one name: it was also known as “Les Chevaliers de l’Amour” (the Knights of Love).5 The leader of the gang in each city was referred to as the “Emperor”6—an ironic term given that in 1870 the French had replaced their last emperor, Napoleon III, with a republic.

All this ersatz nobility, however, could not conceal the ugly reality of the Macquereuax’s activities. The gang was reputedly engaged in the large-scale practice of “white slavery” in Denver’s red-light district.7 And it received even more notoriety when one of its reputed members, Richard Demady, was indicted for a murder attributed to the “Denver Strangler,” a serial killer of prostitutes who was active in Denver during this period. (Demady was eventually tried but acquitted and then moved to Brazil.)8

Gabrielle LeRoi’s Story

In a 1906 front-page article in the Rocky Mountain News, a victim of the Macquereaux named Gabrielle LeRoi told the tragic story of her enslavement and exploitation by the gang.9 Gabrielle was born in Rouen, France, but had relocated to Paris to find work after her father, a teamster, was crippled in an accident. For a while she worked in the French capitol at a milliner’s shop. She did well there, and a girlfriend enticed her to visit some friends in the city’s Latin Quarter.

Gabrielle soon became a frequent visitor to the sophisticated cafes of the Latin Quarter, where she met an American from Boston who charmed her. He later left to go back to America. So when one of the “chevaliers de l’amour” told Gabrielle he could help her find a job as a milliner in America, she listened. Perhaps, she thought, she would even reconnect with her friend from Boston. Soon, she found herself on a steamship headed for America.

It was only when her voyage was well underway that she realized she had been badly deceived. She was forced into third-class quarters with other women being trafficked. She realized she had fallen into the hands of the Macquereaux. Once the ship landed in America, she was threatened with death if she tried to escape, then hustled onto a train to El Paso, Texas. From there she was transported to Pueblo and then ultimately to Denver. She described how during this time well-dressed but cruel men initiated her into the indignities of her life as a prostitute.

The remainder of the article described the challenges law enforcement faced in holding the Macquereaux accountable for their crimes. Other newspaper articles of the time described the fate of women who went to the police to inform on the gang. These women were allegedly assaulted and sometimes murdered.10

The Campbell Law and the Trozzo Case

Perhaps in response to reports like these, in 1909 the Colorado legislature passed an anti-pimping measure known as the Campbell law. The law made it illegal for men to live off the earnings of prostitutes.

Rafael Trozzo, an Italian immigrant, was one of the first defendants tried under the law. Notwithstanding the law’s origins, it is not clear whether Trozzo’s activities involved sex trafficking as opposed to simply being a pimp. His crimes took place in Pueblo, and he does not appear to have been part of the Macquereaux gang. But his case would provide an early and legally significant challenge to the law.

Trozzo, also known as “Blackie,” worked for Pete Ferrone (or Froney), the “king” of Pueblo’s red-light district.11 On July 1, 1910, Trozzo and another man named S. J. Majors were indicted on prostitution-related charges in Pueblo District Court.12 Trozzo was charged in two separate indictments—first with “feloniously engaging and assisting in operating and managing a certain house for the purpose of carrying on prostitution,” and second with “feloniously and knowingly living on and being supported, in part, by the money and other valuable considerations realized, procured and earned by one Winnie Stevens, a female person, through the prostitution of one Blanche Bennett, another female person.”13 The charges were consolidated for trial. Trozzo was convicted on both, and the trial court denied his motion for a new trial. He appealed his conviction to the Colorado Supreme Court.

Trozzo’s Appeal

Trozzo first launched a constitutional challenge to the Campbell law. He argued the law violated article 5, section 21 of the Colorado Constitution, which requires that bills (other than general appropriation bills) have no more than a single subject, and that the subject must be clearly expressed in the title. The law’s title contained two conjunctively linked descriptive clauses: the first defining it as “An act concerning certain forms of prostitution” and the second, “and providing punishments for persons encouraging prostitution in violation of this act.”14 The Court held that the second clause, dealing with punishment, was germane to the first clause, setting forth the subject matter of the Act. Thus, the law’s title did not violate the Colorado Constitution by containing more than a single subject.

In addition, the Court held, the specific activities prohibited within the Act fell under its title. The prohibitions on maintaining a house for prostitution or pimping “all concern[ed] prostitution or certain forms of prostitution.”15 The Court therefore rejected Trozzo’s constitutional challenge.

Trozzo next argued that the trial court had erred by consolidating his cases for trial. He claimed that “the two indictments charged two separate and distinct offenses, which did not arise or grow out of the same transaction, or involve the same crime; that each required separate testimony and separate defenses.”16 But the Court concluded that both indictments involved violation of the same statutory section and arose from the same or connected transactions and the trial court had not erred in consolidating them.

In his third issue, Trozzo challenged the rejection of a line of questioning his defense counsel had sought to use to impeach Blanche Bennett’s testimony. Bennett was the state’s key witness against Trozzo. During cross-examination, his counsel attempted to ask her whether

she had not had a conversation with Pete Ferrone in the city at the corner of River and Kelly streets at a time about two weeks after the arrest of the defendant Blackie, wherein she said if Blackie had gone on her bond she would not have said anything against him; that he had not treated her right; she had it in for him, and that she intended to give him a roughing.17

The trial court sustained the district attorney’s objection, finding the question immaterial.18 It also barred counsel’s attempt to admit Bennett’s statement through Ferrone’s testimony. By contrast, the prosecutor was allowed to ask a state’s witness about a statement that Trozzo’s key witness, Winnie Stevens, allegedly made, that if Bennett turned Trozzo in to the authorities Stevens would “choke her and make her leave town.”19

The Court noted that when Trozzo raised this issue in his new-trial motion, the trial court had conceded it had erred in sustaining the prosecutor’s objection. But the trial court had concluded the omitted testimony was merely cumulative because

[Bennett’s] manner . . . on the stand, the very bitterness of her words, the manner in which she spoke them, her sarcasm and irony, the tone of her voice and her very demeanor both on and off the stand, in the presence of the jury, told them, as plainly as if expressed in words, of her undying hatred of the man whom she says took her money, leaving her but a p[i]ttance to live on.20

The Court rejected the trial court’s conclusion that barring the inquiry was harmless, however, noting that the state was permitted to ask similar questions that showed bias by Winnie Stevens. The jury might have concluded from this that bias by a state’s witness (Bennett) was immaterial, but bias by a defense witness (Stevens) was relevant. More broadly, the Court also rejected the concept that the omitted impeachment evidence would merely have been cumulative:

It would be a dangerous precedent to allow this line of reasoning to be used as an excuse for the rejection of competent evidence in a criminal case, even where the crimes charged are of such a low and degrading nature as those alleged in these indictments.21

Finally, Trozzo challenged several jury instructions. He first challenged  an instruction that allowed the jury to convict him of operating and managing a house of prostitution even if he had not personally operated the house in question, so long as the evidence showed that he “in any manner did aid, abet, assist, advise or encourage” either Winnie Stevens or Blanche Bennett in doing so.22 This instruction was justified based on a provision in the statute that made it illegal to “engage or assist in operating or managing any rooming house or building for the purpose of carrying on prostitution.”23 The Court held, however, that use of broad “aiding and abetting” language in the instruction expanded the scope of criminal liability beyond “engaging or assisting” in operating or managing a house of prostitution, and was therefore erroneous.

In reaching this conclusion, the Court made an interesting point about the way the statute criminalized prostitution-related activities by men and women. If either Stevens or Bennett had been charged with managing or operating a house of prostitution, as females they could only have been convicted of a misdemeanor. A man engaged in the same activity would be convicted of a felony. But under the law of accessory and principal liability, a person who merely aided or abetted a misdemeanor could not be convicted of a felony. This principle did not present a problem, apart from the instruction,24 because it was clear Trozzo had been charged as a principal for his own actions rather than an accessory to either Stevens’s or Bennett’s acts. But the language of the instruction went beyond the charge by suggesting that Trozzo could be convicted of a felony merely by aiding or abetting Stevens or Bennett in running the house of prostitution. This posed a significant legal problem involving principal and accessory liability, and it further illustrated why the instruction was erroneous.

Trozzo next challenged an instruction that informed the jury that if he had received any money from Stevens that she had received from Bennett and if he knew that Bennett had earned the money as a prostitute, Trozzo could be convicted under the statute’s anti-pimping provision. The instruction stated that “[t]he amount or sum he so received, as well as the purposes for which it was given or for which he received it, are immaterial.”25 This language went too far because it eliminated the statutory requirement that Trozzo must have lived on or been supported in whole or in part by the money he received, and because it eviscerated Trozzo’s defense that Stevens gave him the money to repay her debts to him or to redeem jewelry (rather than to support him as a pimp). The Court therefore found the instruction erroneous.

The Court rejected Trozzo’s challenge to a third instruction, but it concluded that the errors in giving the two instructions it had specified were not harmless, even considering the other, proper instructions the trial court had given. Because of the instructional errors and the exclusion of potential impeachment evidence, the Court reversed Trozzo’s conviction.


It is unclear whether Trozzo was ever retried. The Colorado Revised Statutes continue to prohibit both pimping26 and keeping a place of prostitution.27 The Trozzo case, although decided over a century ago, illustrates how the courts must determine the scope of statutes passed to resolve pressing social problems.

Human trafficking remains a serious problem in Colorado and throughout the world. In addition to law enforcement efforts, many nongovernmental organizations have sprung up to confront this problem. One such organization, headquartered here in Colorado, is ALIGHT (Alliance to Lead Impact in Global Human Trafficking), which matches volunteer attorneys with human trafficking survivors.28

Frank Gibbard is a staff attorney with the Tenth Circuit Court of Appeals—(303) 844-5306,


1. “Police Clear Tenderloin of Macquereaux,” Rocky Mtn. News, p.3, col. 1 (Oct. 5, 1907).

2. See id.

3. See id.

4. The word is still used in French slang to refer to a pimp. It may be etymologically related to the Middle Dutch word “makelare,” referring to a broker or trafficker. It is also the likely source of the slang term “mac” or “mack,” still used in English to refer to a pimp. (See, e.g., the 1973 film, “The Mack” starring Richard Pryor.). Speakers of modern colloquial French also use the related term “mec”—a “familiar” term not typically used in polite society—which is roughly equivalent to the English slang term “dude.”

5. “Macquereaux Not to be Tolerated,” Rocky Mtn. News, p. 1, col. 1 (June 30, 1906).

6. See id.

7. The term “white slavery” is something of a misnomer, given that women of various races and ethnicities (including Japanese women, for example) were trafficked for sexual purposes.

8. See, e.g., O’Hare & Dick, Wicked Denver: Mile-High Misdeeds and Malfeasance 71-72 (History Press 2012).

9. “White Slave Tells Story of Her Life,” Rocky Mtn. News, p.1, col. 1 (June 29, 1906).

10. See, e.g., “Fight Almost Fatal: One of the Macquereaux Seeks Revenge,” Aspen Daily Times, p. 1, col. 6 (July 25, 1906); “Secret Society of Frenchmen,” Colo. Wkly. Chieftain, p. 1, col. 7 (Nov. 1, 1894).

11. “Grand Jury Orders First Arrest in Corrupt Red Light Political Gang,” Pueblo Sun, p.4, col. 4 (Mar. 4, 1910).

12. “Two White Slave Dealers are Convicted in Pueblo,” Rocky Mtn. News, p.5, col. 5 (July 2, 1910).

13. Trozzo v. People, 117 P. 150, 151 (Colo. 1911).

14. Id. at 152 (internal quotation marks omitted).

15. Id.

16. Id.

17. Id. at 153.

18. See id.

19. Id.

20. Id.

21. Id.

22. Id. at 154.

23. Id. (emphasis added) (internal quotation marks omitted).

24. The Court did not consider whether differential punishment of male and female offenders violated the Equal Protection Clause. Trozzo was decided in 1911, after all.

25. Trozzo, 117 P. at 155 (internal quotation marks omitted).

26. See CRS § 18-7-206.

27. See CRS § 18-7-204.

28. By way of disclosure, the author is a regular contributor to ALIGHT,, and supports its mission to aid victims of human trafficking.