WASHINGTON (AP) — Black people are arrested for possessing marijuana far more often than white people, even though marijuana use by both races is about the same, the American Civil Liberties Union reports in a new study.

The ACLU’s analysis of federal crime data, released Tuesday, found marijuana arrest rates for black people were 3.73 times greater than those for white people nationally in 2010. In some counties, the arrest rate was 10 to 30 times greater for blacks. In two Alabama counties, 100 percent of those arrested for marijuana possession were black, the ACLU said.