"The Massachusetts Chiefs of Police, Massachusetts Sheriffs Association and the state's district attorneys have all come out against marijuana legalization, according to the opposition campaign. 

Suffolk County Sheriff Steven Tompkins said after the press conference that he understands arguments being raised about "people falling into the criminal justice system," but would "rather err on the side of caution" on marijuana policy.

"I'm always concerned, particularly as a sheriff, about who goes to jail and who does not, and when you look at the overwhelming number of people of color, black and Latino, that are in our incarceration facilities, yes, I am very concerned about that," Tompkins told the News Service. "That said, I have to balance that with health issues and I have to balance that with what I see going on."

Tompkins said he was particularly concerned about the ability to manipulate levels of the psychoactive component THC in marijuana edibles and the potential for such products to appeal to children."

Read more: