Why Is Maria Ruiz in Prison?
During season four, we see that Maria is the daughter of a Dominican equality activist. As a teenage girl, she sees a Mexican guy dropping money into a bush while running from the cops. She grabs it and finds him later to give it back, but that's not actually what leads to her arrest. Instead, in season seven, it's Maria decisions as a manager for a retail clothing store that put her away.
We find out that the man she's cheating on her boyfriend with convinces her to switch out real True Religion jeans in her store with counterfeits he has from overseas, and the two of them will split the extra cash. Unfortunately for Maria, three government agents catch on to their scam and arrest her, throwing her in prison.