"20/20" Helps Viewers in Desperate Search for Their Biological Families, Airing Friday, January 29, 10 p.m. on ABC

"20/20" investigates family mysteries sent in to ABC by viewers searching for their long lost family members. With the help of investigative genealogist Pamela Slaton, whose passion is reuniting people, Elizabeth Vargas and "20/20" set out on three emotional journeys:

· For 44 years, Donald DJ Williams, who was discovered just four days after Christmas, on December 29, 1971 in a nativity scene in a Houston church as a baby, knew nothing about his biological family. After watching a "20/20" last November where Slaton helped solve a decades-old mystery, DJ turned to Slaton and ABC for help. Will DNA testing bring DJ closer to the truth? Vargas and DJ return to the church where he was abandoned with hopes of a breakthrough.

· Growing up as an only child, Gina Lozada of Long Island always wanted a sibling. Yet after her father died, Gina's mom revealed a family secret - that her dad had fathered a son with another woman before they were married. For almost three decades Gina ran into dead-ends while searching for her brother, but she never gave up hope. Will a strange encounter with a New Jersey man at an Atlantic City casino be the turning point for Gina in her life-long quest to find her sibling?

· Mississippi native Amanda Holdiness, 31, has always wanted to meet her biological father. The only problem is her mother, Vivian, refused to reveal his true identity saying she was all Amanda ever needed. Vivian finally gave Amanda a name last year, and, after watching "20/20" and Slaton solve another case, she turned to Slaton to help find him. They traveled to Florida and Louisiana. Will it prove to be successful journeys?

"20/20" airs on FRIDAY, JANUARY 29 (10:00-11:00 p.m. EST) on ABC.

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