Juvenile Hall incarceration rates in San Mateo County are on the decline, matching a statewide trend that shows youth crime in California has plummeted to an all-time low.
The downturn is documented in a new report from the California Sentencing Institute (CASI). The report includes data and interactive maps about rates of both adult and juvenile arrests and incarcerations from each of California's 58 counties.
The latest data for 2011 from the California Department of Justice’s Criminal Justice Statistics Center show arrests of youths under age 18 fell by 20 percent in California from 2010 to 2011, reaching their lowest level since statewide statistics were first compiled in 1954.
In San Mateo County, the number of youth arrested fell by 147 between 2009 and 2010. Incarceration rates have fallen from 276 youth per 1,000 arrests in 2009 to 249 in 2010 for youth ages 10-17, the report showed.
Some of the factors are policy shifts. A statewide marijuana reform law, introduced by Marin's state Senator Mark Leno, went into effect on Jan. 1, 2011, reducing most simple marijuana possessions to an infraction involving a mere citation rather than criminal arrest. That reform reduced youth marijuana possession arrests by 61 percent statewide in one year, from nearly 15,000 in 2010 to 5,800 in 2011.
Here are the annual bookings and average daily population at San Mateo County Juvenile Hall for the past three years:
*per 100,000 youth ages 10-17
**per 1,000 juvenile felony arrests