Film with a brother and sister trying to track down the mysterious background of their father, and encounter fascist ghosts and their victims

I think I watched this 5-6 years ago with my wife as a movie that we checked out from our library after having seen the trailer on another film we watched. I’m pretty sure it was in English, and had a brother and sister, I think in the United States in roughly contemporary times, going on the road (I think they were noted to be skipping school in the process) to track down clues about their father’s past (I believe he was estranged from the family, and had recently been reported as dead).

I remember one early scene has them stopping at a rundown hotel in an old house where they encounter ghostly apparitions that shake the doors and stalk them. A later scene has them at a hospital (I think after one of them had been injured by the ghost), and they start seeing manifestations of the haunting, whereupon they try to warn the people at the hospital, but without much success. Eventually, they learn that their father was in a Spanish-speaking country (I think maybe South America?) where he worked with the government as a doctor and torturer, I think primarily with young girls. There was definitely a moral and religious aspect to it, maybe girls who had been found having extra-martial sex?

As I recall the end, the film ends with the sister trapped among the ghosts, including the one of her father, who start strapping her down to the operating table to punish her for her indiscretions.