More than 40 employees lost their jobs last month; most quit voluntarily after being asked to bring in documents that verified their status to work in the U.S.
"It strikes me as just an irresponsible company practice that sets a bad environment in that Target store; if I worked there, I'd be nervous about working for that employer," Anamaria Loya of La Raza Centro Legal said.
Target issued a statement saying, "We recently investigated an allegation of possible unauthorized workers at our store in Walnut Creek. All team members questioned in connection with this investigation were given the opportunity to provide target with further information to re-establish their ability to work in our store."
The retailer also insists it complies with immigration laws while treating its workers fairly.