Transcript for In David Temple's 2nd murder trial, defense tries implicates neighbor: Part 9
This second jury on the David temple trial has sat through opening statements. They've been hearing evidence. But one of the biggest shoes to drop won't even happen in front of the jury. It's in the news. Heather Scott drops a bomb. She's filed for divorce in the middle of the trial. I remember going, "Whoa. Wow." They go through all this drama together during their marriage. She stands by her man. And then suddenly in the midst of the second murder trial, she drops him like a hot potato. I think it's fair to say that David and Heather had a very complicated relationship. Why she decided to file for divorce, I wouldn't be able to talk about or speculate. But back in the courtroom, David temple's defense team is arguing that the biggest suspect in the Belinda temple murder is not her husband, but Riley Joe Sanders. They are arguing that he had a grudge against the teacher. Coming into this second trial, prosecutors know that the defense is going to be pointing the fingers at Riley Joe Sanders. So prosecutors decide to deal with this head-on. They call him to the stand as part of their case. Why don't you tell these folks your name? Riley Joe Sanders III. Riley Joe Sanders is 37 years old. But at the time of the crime, on January 11th, 1999, he was just a 16-year-old boy. Let's skip the niceties. Let's cut to the chase. Tell these folks, did you have anything to do with Mrs. Temple's murder? No, did not. Did you have any hard feelings against Mrs. Temple for ratting you out on your skipping school? No. Did you act any differently towards her? No. The prosecutors walk Riley Joe Sanders through what he did the day of the murder. And it starts off with him talking about how he skipped the last period of the school day. And did you skip alone or with someone? I was with a buddy, Cody Ellis. So when you and Cody got to your house, what did y'all do? Rolled a joint. Now, just for the record, I think we all know what that means, but when you roll a joint, what are you using it with? Paper. Touche. That was good. What was the substance inside the paper? There we go. Okay. Prosecutors want to show that the worst thing that Riley Joe Sanders is guilty of is smoking some pot and cutting class. Joe and Cody are riding around the back streets of Katy. And what are they doing? Smoking a joint. And then Joe says he dropped Cody off at home. Joe ends up going to a couple of more friends' houses in an effort to score some more marijuana. He doesn't find any so he ends up heading back home. What did you then do? Turn the TV on, laid on the couch, then passed out. How'd you wake up? By my father. Did you go outside? Yes, ma'am. What'd you see? A bunch of cops. The defense wants the jurors to believe a darker chain of events. The defense grills Sanders' father about shotguns that he owns. Did Joe have blanket permission from you to take your shotguns out? Yes, sir. So he could take your shotguns from your house at any time he wanted and go shooting? Yes, sir. Did you own or do you own an h&r single-shot shotgun, Back then, I did. Yes, sir. So the testimony from his dad, that he owned the same kind of shotgun as was used in the murder, that his son could have access to it whenever he wanted, could become that "A-ha" moment for the defense where jurors could say, well, that's pretty important. The wadding that was found in Belinda's brain was from a federal shotgun shell, the same kind of shotgun shell that was in the Riley Joe Sanders shotgun. And this spent double-aught buckshot federal shell could have caused the death of Belinda temple. Yes, sir. It could've. The defense hopes that the fact that Riley Joe Sanders had access to that weapon whenever he wanted was effectively putting that murder weapon in his hands. The prosecution says, not so fast. They want the jury to know that there's somebody else who had access to that same kind of shotgun -- the defendant, David temple. The defendant was a hunter. He had hunted with a 12-gauge shotgun throughout his life. And so, sure enough, they call one of his hunting buddies. While you were growing up in through high school, did you have occasion and hunt with the defendant? Yes. When you were doing all of this hunting, what did you hunt with? A 12-gauge shotgun? When you hunted with the defendant, did he use 12 --? Yes, ma'am. Prosecutors did their best to argue that at one point David had possessed a 12-gauge shotgun. But the question is, where is the murder weapon? Is there a clue in these surveillance videos?
This transcript has been automatically generated and may not be 100% accurate.