Rudy Valdez at first thought the 15-year prison sentence given to his sister Cindy Shank was a clerical error. The judge had probably meant to give her 15 months, he reasoned. Shank, whose sentence was later commuted, had been found guilty of conspiracy on drug charges, related to the crimes of an ex-boyfriend who had died years ago. Valdez says he thought he’d be able to fix it.

But, Valdez says, a quick Google search showed there hadn’t been a mistake. Shank was one of thousands of people in the U.S. sent to prison under mandatory minimum sentences — automatic prison terms mandated by the government. Roughly six years before her conviction, Shank lived in Lansing, Mich., with a boyfriend who dealt drugs and was later killed. She initially faced state charges in 2002 for conspiracy to distribute cocaine, but the case was dropped. In 2007, Shank was married and had two children, with a third on the way, when she was arrested on revived charges of conspiracy in the federal government’s investigation into her boyfriend’s drug enterprise. After a trial that same year, Shank was sentenced to 15 years, the mandatory minimum for her charge, and sent to federal prison after the birth of her third daughter.