It’s hard to tell. She’s faced a ton of criticism when she was the District Attorney in San Francisco and Attorney General of California (who can forget this exchange in the democratic debates). But she is pitching herself as a “progressive prosecutor” and there are some who have supported this view, including this public defender. Last September, Harris release her criminal justice plan, which sounds pretty good (summarized from Newsweek)
Among the goals she listed were ending mass incarceration, investing in programs aimed at reducing crime, legalizing marijuana, making changes to the criminal justice system's "sentencing schemes, stopping private prison use and encouraging prisoners' rehabilitation, the last of which was a callback to her earlier "Back on Track" program.