Marijuana arrests have plummeted in Washington State and Colorado since they legalized marijuana. If/when Oregon, Alaska, and Washington D.C. legalize marijuana next month, I'd expect marijuana arrests to drop there as well. However, while many states are seeing a decrease in marijuana arrests due to legalization or decriminalization, there are still many states that are seeing an increase in marijuana arrests. Per the Huffington Post:
While marijuana arrests have been decreasing in many states, in two-thirds of the states actually, in 17 states marijuana arrest rates have been increasing by at least an average of 1% annually from 2008 to 2012. Of these 17 jurisdictions, 12 had an annual increase greater than 2% and 8 greater than 3% per year. Collectively they account for 28.8% of the population of the United States and 44.6% of the arrests for marijuana offenses.
These states and their annual average increases are South Carolina (11.6%), Washington, DC* (7.7%) South Dakota (7.7%), North Dakota (5.5%), Utah (4.5%), Illinois* (4.3%), Montana (3.5%), Idaho (3.2%), Virginia (2.6%), New York (2.4%), New Jersey (2,4%), Oregon (2.1%), Tennessee (1.7%), Wisconsin (1.2%), Vermont (1%), Michigan (1%), and West Virginia (1%). (*The Washington, DC and Illinois data are for the period 2008 to 2011.)
Those marijuana arrest numbers break my heart. No one should ever be arrested for a plant that is safer than alcohol. No jail bed should ever be occupied by someone that has been arrested for marijuana instead of the jail bed being reserved for a violent criminal. It's time every state took a new approach to marijuana laws.