Jenny Cain would never forget the hot Massachusetts summer day fate knocked at her door. Fate was a teenaged boy with rumpled clothes, a motorcycle, and a shocking but credible story: Jenny's husband, Geof, was his biological father. The boy, David Mayer, wasn't looking for an emotional reunion, but he did have an agenda. His parents -- and he was quick to make the point that Geof was nothing to him -- died earlier in the year, a murder/suicide according to the police. The cops were wrong, David said, and Geof was a cop, and he owed it to David to prove that Ron Mayer did not kill his...