reporter: and it was a hunt the prosecution said. the investigator told the jury he d used cellphone data to track the moorers movements. in the days before the disappearance, they showed up near heather s workplace, some of the bars she liked, even her home. the prosecution suggested the couple was stalking her. then in the early hours of december 18, 2013, with heather s roommate out of town, the prosecutor said the couple struck. it began here. the prosecutor showed the jury surveillance video of sidney walking into a walmart and purchasing a pregnancy test for heather. soon as they leave from walmart, they go and call her. why? cause the test is for her. reporter: the prosecution s theory was that sidney had called heather to come and get the test. take it and then meet up with him later at the landing. they said what she didn t know was that tammy would be there too. there s no doubt sidney is
tammy and sidney had been stalking heather. i would say you could compare their phone activity to anybody else s who lived and worked in the area. those are where the nightclubs are. there are restaurants there. it would appear that i were stalking her as well if you just looked at where my phone went. reporter: the defense said that what the jury really needed to understand was a simple fact. no piece of evidence put tammy at the landing. if anything, her alibi placed her miles away. did tammy s children stay in the house with you where your mother polly lives? yes. reporter: tammy s sister ashley told the court she was baby-sitting tammy s kids on the night of december 17, 2013. she said tammy and sidney went out together in the hours leading up to heather s disappearance. but ashley remembered when her sister came home. she texted me that night saying that she was home. do you know about what time that was?
literally chains him to the bed at night. that played back into the state s theory that tammy was the controlling one in this relationship. she was the one who wore the pants in this relationship. reporter: but as angry as she was at sidney for cheating, prosecutors said, tammy was furious with heather. she d sent her several texts. the prosecution said some of them were threats. heather was really afraid of tammy. she was. her friends had played a prank on her one time at work where they pretended to be tammy calling heather s phone and she was absolutely terrified. reporter: and the prosecution said if there was any doubt about the way tammy felt, just look at this nasty facebook post tammy had written after heather disappeared, calling her a psycho whore. she could ve said, oh, i m so sorry this girl s missing and hope you find her and left it alone. but, no, she goes on the attack. tammy is the one with the motive. she is the hunter.
a fire of jealousy was lit in the defendant. she was livid. she was angry. reporter: an anger that became something more sinister when tammy heard a rumor around town. heather might be pregnant with sidney s baby. when this gets out and becomes common knowledge, the fire, the jealousy that is in tammy moorer explodes into utter rage. reporter: prosecutors said that rage wouldn t be satisfied until heather was out of the way. they said it was obvious how much the affair had upset tammy by the way she had treated sidney afterwards. she said she beat the hell out of him. reporter: this witness said sidney had a tattoo of tammy s name across his abdomen. his understanding was that tammy made sidney get it. the state theory was that was tammy s way to say you re mine and you re never going to be anyone else s. reporter: the prosecutor said tammy had even chained sidney to the bed with handcuffs. i m not speaking figuratively to you right now.
the bait in this hunting. he s the bait. reporter: prosecutors admitted they couldn t say what happened to heather at the landing. but they asked the jury to use their common sense. an investigator showed the jury a photo of several items found on the moorers property. there is a spent shotgun shell here, there is a bag of concrete mix here and off to the side up here is some kind of a bottle of a cleaning solution. reporter: the prosecution suggested it was nothing less than a kidnapping kit. what the moorers might have needed to kill heather and dispose of her body. how hard was it for you being in that courtroom every day, hearing these details, having to see tammy? most days when i woke up i didn t want to come to the trial. but i went because when you see your parents hurting, you wish that you could take all their pain away.