During a panel discussion about sex trafficking at the Centennial Hall in Colorado Springs earlier this year, an audience member asked a question that seemed to stump most of the half-dozen guest speakers.
Did the legalization of marijuana bring in more pimps and prostitutes to Colorado?
Colorado Springs police Sgt. Craig Simpson, who supervises the department's Human Trafficking Unit, was the only one to offer an answer: Colorado marijuana provides pimps a reason to move into the state while the drug lures women and men into the sex trade industry.
But he quickly provided a caveat.
There's no statistical proof from law enforcement agencies to suggest that the legalization of marijuana is connected to sex trafficking across the state. Simpson's statement centers around interviews with pimps and prostitutes.
"Everything is observational and anecdotal," Simpson said recently.
This kind of statement irks Mason Tvert, a spokesman for the Marijuana Policy Project, the country's largest organization focusing on marijuana policy reform. He believes law enforcement, city and state officials are blaming marijuana for everything they can't handle.
Tvert said, for example, that Denver Mayor Michael Hancock wrongly alleged that legal marijuana attracted "urban travelers" to the city and contributes to assaults and other violent behavior along the 16th Street Mall.
"If they would spend more time addressing human trafficking and less time trying to roll back the state marijuana laws, perhaps we might see more success in reducing human trafficking," he said.
Also, he says that legal marijuana has also weakened cartels because "they have less money to subsidize their other activities," including prostitution.
The legal recreational marijuana industry grew to $5.7 billion in 2015 - up from $4.6 billion in 2014, according to data from Arcview Market and New Frontier research groups. The report also says that the industry is projected to make $22 billion by 2020. Recreational sales of the drug became legal in January 2012.
While Tvert says police are reaching to make the marijuana-sex trafficking connection, there have been high-profile cases that may back up their claims.
During the Denver 420 Rally in April that attracted thousands of people, authorities saved five children, including a 15-year-old brought from California, who were escorted to the event to be sold for sex, according to an FBI news release. Also, nine adults were arrested on trafficking charges along with 26 adults arrested for prostitution.
"Whenever an event draws people from around the world, you will see an increase in sex trafficking," Thomas Ravenelle, Denver's FBI special agent in charge, said in a statement at the time. "The reality is major events will always have some organized criminal activity, including people who facilitate and profit from prostituting adults and children."
Citing two news articles, a report by a law enforcement task force called the Rocky Mountain High Intensity Drug Trafficking Area suggests that "the legalization of marijuana is fueling a sex tourism in Colorado."
The report - led by task force director Tom Gorman, who fought the legalization of marijuana - has been criticized because information provided by law enforcement agencies is voluntary.
Roger Patrizio, chairman of the Human Trafficking Task Force of Southern Colorado, believes there is a connection between marijuana and sex trafficking, especially at big marijuana celebrations and big sporting events
"I don't think it's the seediness of that drug," he says. "I think there's more tourists coming out to Colorado to party with marijuana because it's legal, so when they drink and get high, the next thing they're looking at is girls or boys."
The lack of statistics worries at least one expert on human and sex trafficking.
"Yes, it does concern me, because I feel that at present we have too little data to be able to make effective strategies to protect our vulnerable populations, which include children, victims of domestic abuse, and homeless youth, who tend to be common targets of sex traffickers," said Aditi Mitra, a faculty member at the University of Colorado at Colorado Springs' Office of the Provost and executive vice chancellor for academic affairs. "If, indeed, there is a correlation between legalization of marijuana and increase in sex trafficking, then we need to be cognizant about this situation."