duenas back yard. and as for those screams, heard by teenagers a couple blocks away? >> the entire block where mark. the woman next door sleeps with her window open, hears nothing. the person on the other side of the house is jason duenas who has his window open. he hears nothing. >> reporter: the defense put on a witness who said karen told her the very week of the murder that she and mark were making plans for a bright future together. and the idea that mark would kill karen so he could pursue a happily married woman from idaho he hadn't seen in more than 30 years was simply ridiculous, said the defense. >> it sounds like a great motive when you look at it from a distance, but then when you get to it, it sounds like puppy love. >> reporter: the defense rested its case in a matter of hours. >> when it went to the jury, how'd you feel about it? >> oh, i was pretty confident. you could see in the jury's face that they weren't buying this. >> reporter: then, something odd happened. the day the jury went out, a female juror overslept. and rather than delay the case, the judge replaced her with an alte