would ultimately come right back to his loved. once >> in closing arguments, the prosecutor said there was no doubt diana lovejoy and weldon mcdavid had conspired to kill greg mulvihill. >> they didn't planned for jason kovach. they didn't plan for a by bright bike light to light up mr. mcdavid. and they did plan to get caught. no reason to kill, he had 120,000 reasons to kill. >> what would the jury think? first, let's see what you think. here what weldon and i and i had to say when we visited them in jail. >> coming up -- a defendant's biggest regret. not what you might think. >> if i could only take back one thing, i would take. that >> and drama in court. when dateline continues. ues. ♪ ♪