The headline screams "DC's legalized weed is one year old, and crime has cratered."

Not so fast.

Washington, DC, did indeed legalize marijuana on February 26, 2015, and since then, violent crime has increased substantially.

According to the latest crime data from the Metropolitan Police Department, the number of violent crimes during the first three months of 2016 is up 15% compared to the same time frame last year. By comparison, population growth in the area is only 2% per year.

After 20 years of nearly continuous decline, the number of homicides in DC last year shot up 54% in the legal pot era. If the first part of 2016 is any indication, they are on-pace for another increase this year.

While it is still early in 2016, the 15% increase in the number of violent crimes so far translates into a 13% increase in the violent crime rate for the year if the trend continues and population growth comes in as expected.

To see how anomalous this possible increase would be, since 2003 the year-to-year change in DC's violent crime rate has only ever ranged between a 11% reduction up to no effective change (i.e., <0.4% increase). In other words, DC's violent crime rate has either declined or remained stable during each and every year since at least 2003 -- up until marijuana was legalized, and after that the pattern appears headed for a major reversal.