President Donald Trump’s Department of Justice is set to begin a wide crackdown on marijuana according to the Hill.

Pro-Civil Rights groups fear that President Trump’s Task Force on Crime Reduction and Public Safety, being led by Attorney General Jeff Sessions will issue a bogus study linking cannabis use to an increase in violent crime.

Inimai Chettiar, director of the Brennan Center’s Justice Program, told the Hill, “The task force revolves around reducing violent crime and Sessions and other DOJ officials have been out there over the last month and explicitly the last couple of weeks talking about how immigration and marijuana increases violent crime.”

Attorney General Jeff Sessions described the marijuana task force as something meant to prevent violent crime, “Task Force subcommittees will also undertake a review of existing policies in the areas of charging, sentencing, and marijuana to ensure consistency with the Department’s overall strategy on reducing violent crime and with Administration goals and priorities,” the Attorney General wrote.

There is no scientific evidence that marijuana drives violent crime. Studies have shown the opposite effect according to Think Progress:

Denver saw a 2.2 percent drop in violent crime rates in the year after the first legal recreational cannabis sales in Colorado. Overall property crime dropped by 8.9 percent in the same period there, according to figures from the Drug Policy Alliance. In Washington, violent crime rates dropped by 10 percent from 2011 to 2014. Voters legalized recreational marijuana there in 2012.

Medical marijuana laws, which have a longer track record for academics than recreational pot legalization, are also associated with stable or falling violent crime rates. In one 2014 study of the 11 states that legalized medical pot from 1990 to 2006, there was no increase in the seven major categories of violent crime and “some evidence of decreasing rates of some types of violent crime, namely homicide and assault.”

Senator Rand Paul has promised to fight the Attorney General if he attempts to crack down on marijuana use in states that have legally permitted its use.