Marijuana Arrest Rates (IMAGE) Washington State University Caption Marijuana arrest rates were already on the decline but plummeted after Colorado and Washington authorized retail sales late in 2012. Credit David Makin, Washington State University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.