Whites and blacks smoke weed at nearly similar rates (actually whites smoke more), and yet blacks get arrested for it far more often. This report reflects more good work by Queens College professor Harry Levine:
From 2006 through 2008, police in 25 of California's major cities have arrested blacks for low-level marijuana possession at four, five, six, seven and even twelve times the rate of whites.Doesn't that matter?
The City of Los Angeles, with ten percent of California's population, arrested blacks for marijuana possession at seven times the rate of whites.
These racially-biased marijuana arrests were a system-wide phenomenon, occurring in every county and nearly every police department in California. They were not mainly the result of individual prejudice or racism. In making these arrests, patrol officers were doing what they were assigned to do.