What Happened to Two Teenage Sisters Who Disappeared for Two and a Half Years During Their Parent’s Bitter Divorce and Custody Battle, Airing on “20/20,” Friday, April 8, 10 p.m. EDT on “BAD BLOOD” ON “20/20 SATURDAY” Airs April 2, 10 PM ET on ABC

Did a bitter divorce and custody battle drive two teenage sisters to disappear for two and a half years so that they would not end up living with their father, whom their mother alleged was abusive? Elizabeth Vargas’ report airs on “20/20” airs FRIDAY, APRIL 8 (10:00–11:00 p.m. EDT) on the ABC Television Network.

Sandra Grazzini-Rucki and David Rucki’s two teenage daughters vanished from their Minnesota home in April 2013. At the time, Sandra and David were embroiled in a contentious custody battle, with Sandra alleging that David had been physically abusive to her and the children. Police quickly suspected that Sandra knew more than she was saying about where her daughters were, but she insisted she had nothing to do with their disappearance.

Police then began to float an unusual theory - that possibly Sandra hid her daughters away using a network made up of critics of the family court system who believe judges routinely punish mothers who allege abuse, placing their children with dangerous fathers. Sandra was eventually arrested and charged with three felony counts of deprivation of parental rights. While in jail, her two daughters were discovered by police. The girls had been hiding for two and a half years, living on a rural horse farm in northern Minnesota.

“20/20” has exclusive television interviews with Sandra Grazzini-Rucki, the girls’ mother, and with their father David Rucki. The hour also includes interviews with a young man who escaped a father he calls abusive using a loosely organized “ underground;” with the horse farm owners, now facing charges, about why they agreed to keep the girls for so long , and with Sandra and David’s oldest son Nico – who tells a very different version of life inside the Rucki home.

“20/20” is anchored by Elizabeth Vargas and David Muir. David Sloan is senior executive producer.