San Francisco and San Mateo are both turning to supervised release to reduce their jail populations under the state's realignment program.

The two counties expect different outcomes.

In San Francisco, about half of the 247 cases prosecuted under realignment have received so-called split sentences. Instead of two years in jail, for example, a low-level offender gets a year inside and a year with an electronic ankle bracelet.

District Attorney George Gascon says supervised release is the way to rehabilitate defendants. "We actually can be more effective in reintegrating people into the community when we put a lot of services around them and [under] close supervision in a community setting."

San Mateo County is granting split sentences to almost all defendants eligible under realignment, according to Sheriff Greg Munks. But Munks says, saving money is the motivation.

"As a county sheriff, I am concerned. I think even the most optimistic folks are expecting some increase in crime. And I'm just hoping that it's not a drastic increase in crime."

Gascon and Munks say it's too soon to tell what impact realignment is having on public safety.