SAN FRANCISCO — Colby Freeman has worked hard to get his foot in the door to work in a district attorney’s office when he earns his J.D. this May. The University of San Francisco School of Law third-year has volunteered at the San Francisco DA’s office for the past four years; this semester, he says, he’s averaged 45 hours a week.

But in this economy, the door of opportunity is getting pretty jammed with feet.