An American Crime (2007)

The true story of suburban housewife Gertrude Baniszewski, who kept a teenage girl locked in the basement of her Indiana home during the 1960s.

IMDB

Storyline
Based on a true story that shocked the nation in 1965, the film recounts one of the most shocking crimes ever committed against a single victim. Sylvia and Jennie Fae Likens, the two daughters of traveling carnival workers are left for an extended stay at the Indianapolis (3850 E. New York St. is hardly suburban, nor was it in 1965, by any stretch of the imagination.) home of single mother Gertrude Baniszewski and her six children. Times are tough, and Gertrude's financial needs cause her to make this arrangement before realizing how the burden will push her unstable nature to a breaking point. What transpires in the next three months is both riveting and horrific, leaving one child dead and the rest scarred for life.