What makes someone fit to be a parent? Amid competing claims and accusations, adults in conflict sometimes lose sight of what is in the best interest of a child. 48 HOURS correspondent Bill Lagattuta reports that Aaron and Lynda Kass, of Brentwood, Calif., have raised 2-year-old Spencer Kass as their own since the day his birth mother, Crystal Kane of Texas, gave him up for adoption. Kane's only demand was that it be an open adoption. As for the biological father, the Kasses' adoption attorney said he would not be a problem. However, Michael Elskes, of Houston, had no idea his son was put up for adoption and never gave his permission. As soon as he received a letter from the Kasses' attorney asking him to relinquish parental rights, he refused and filed a court order to take Spencer away. Thus began the two-and-a-half-year cross-country custody battle to win him back.