Despite police fears that legal marijuana businesses attract crime, including under-the-table drug dealing, weapons violations, and robberies, a new study says the opposite might be the case.

Researchers at the University of Texas at Dallas analyzed major crimes from 1990 to 2006 in the United States, paying particular attention to early medical marijuana states:

Alaska (1998), California (1996), Colorado (2000), Hawaii (2000), Maine (1999), Montana (2004), Nevada (2000), Oregon (1998), Rhode Island (2006), Vermont (2004), and Washington (1998).

Crime across America -- homicide, rape, robbery, assault, burglary, larceny, and auto theft -- decreased during that time. But the study, published this week in the journal PLOS ONE, states:

The rate of reduction appears to be steeper for states passing MML laws as compared to others for several crimes such as homicide, robbery, and aggravated assault. The raw number of homicides, robberies, and aggravated assaults also appear to be lower for states passing MML as compared to other states, especially from 1998–2006. These preliminary results suggest MML may have a crime-reducing effect.However, 2006 is a year in which medical marijuana dispensaries were just starting to open in earnest in California, so we’d cast some doubt on this analysis.

While medical marijuana was legalized by voters here in 1996, SB 420, a state bill that created ID cards and opened the way for collectives to open, wasn’t signed into law until 2003. At best, that gives us 3 years of crime to look at. But like we said, most dispensaries didn’t hit the scene until 2006 at the earliest, and that’s just in pioneering California.

We don’t doubt that crime associated with dispensaries is negligible, but this study’s time frame makes it almost useless.

In any case, retired cop Neill Franklin of Law Enforcement Against Prohibition, was encouraged by the publication:

It must be difficult to be an opponent of marijuana reform. They can’t make arguments against legalization based on logic and facts so they must constantly resort to fear-based hypotheticals and anecdotes that keep getting proved wrong by systematic study. I feel for them. I really do.

Editor's note: This article originally published on the 420 Times on March 27, 2014.

Photo Credit: David McNew / Getty Images