Civil charges for attempted voter intimidation were sought by the Bush administration, but later dropped against three of four defendants after Obama took office. Republicans accused the DOJ's political leadership of interfering in the decision.
Though Perez had not yet been confirmed to oversee the civil rights division when the decision was made, he said in testimony to Inspector General Michael Horowitz in May 2010 that politics played no part in the decision.
Horowitz was not satisfied with Perez's account of the situation, saying in his report that Perez should have tried to get more information before testifying.
Perez was not accused of any wrongdoing, but he has been criticized for not doing enough to improve what the inspector general described as a dysfunctional department.
Before rising to the Justice Department position, Perez led Maryland's Department of Labor, Licensing and Regulation. That office is charged with "safeguarding workers, protecting consumers, providing a safety net and cultivating a thriving workforce," according to its website.
He also spent 12 years as an attorney in the Justice Department's civil rights division, rising to become deputy assistant attorney general in the 1990s.
Perez also worked for the late Sen. Edward Kennedy, a Massachusetts Democrat, and spent the final two years of the Clinton administration as head of the Health and Human Services Department's civil rights office.