months before shirlene van gundy died, she asked her children to investigate should anything happen to, ken wakisaka, was on trial for her murder. prosecutors argued ken strangled his wife. the defense insisted she overdosed. ken was about to learn his fate. then a chance meeting would turn this case upside down. here's keith morrison with "the vow." keith morrison (voiceover): two tenacious daughters made a promise to their mother and were hoping to keep it. but now, it was up to 12 other people-- a jury. keith morrison: were you in the court when the verdict was read? yes. tell me about that. what a huge relief to hear those words-- "we, the jury, find ken wakisaka guilty of murder in the second degree." is-- it was amazing. keith morrison (voiceover): ken was, well, surprised would be an understatement. i didn't expect this at all. keith morrison (voiceover): but these two? i was a really happy girl. you know, i'm like, the system worked, you know? it worked. keith morrison (voiceover): ken, who still maintained his innocence, was sentenced to life in prison. and that would be it, e