never in his life. >> reporter: lonnie lancto had known cara and j.j.e she and j.j. fell in love. did she have a reasonable argument that maybe she thought she was defending her life? >> not at all. he wasn't a violent person. she has -- she has no other defense but to tell you that. >> reporter: private lives, as we all know, can hide cesspools of stories best left untold. but, no secrets in a murder investigation. the detectives had to know, what was the nature of cara and jj's 20 year relationship? for example, that chance meeting on the beach years earlier when they were divorced. cara said it just happened. the detectives said she made it happen, tracking him down to an out of the way beach. >> she actually told us you know, "i'm" -- "i'm" -- "i'm walking on this beach that's nowhere near my house," and i say, the next man i walk into" -- "he" -- "he's gonna be it." >> reporter: he's the one? yeah. >> and it ends up being jj, you know, wasn't reasonable. >> maybe in the movies, i guess that might happen. >> reporter: calculating, said the detective