it? >> yes. i could not believe she would allow her defense to be "i did it." >> reporter: but there was a reason, said the defense -- giselle had been provoked. she killed michelle in the heat of passion. michelle, she claimed, was a lying schemer who had been busy stealing what little giselle had left in life -- her family. marc klaas watched from the back of the courtroom and was disgusted. >> i don't think character assassination is a defense. i think that if you're going to defend against the indefensible, you have to find a better way of doing it than to vilify the victim. >> reporter: but ford was worried the defense just might work. >> if i come in as a defense lawyer and i say, "we're going to tell you that my client did it, even though the district attorney has the burden of proof. but we're going to tell you why it happens because that's the most important thing." >> reporter: that's something the d.a. can't tell you.