When Veronica found the cameras in the pool house, I didn't even think of it as Logan being kinky and wanting to film their sexual escapade. My mind immediately went to, "OMG AARON IS SO THE KILLER!!!11!!!" First of all, Aaron is fucking creepy with his over-protectiveness as a father. We've seen that with Trina, and he made a little, "You'll see that everything I do is for you," speech for Logan in this ep. The cameras? I don't even think Logan knows about them. Since Aaron was away for a good chunk of Logan's life, he installed the camera so that he can keep tabs on him. Or he enjoyed watching his son getting it on with girls, whatever. Anyway, he knows that Logan and Lilly aren't together because she's seeing Weevil (or whoever) behind Logan's back and Logan made out with some girl at a party. From the teaser, we know that Logan came home early from Tijuana. He and Lilly met, had another fight, and Logan leaves Lilly alone in the poolhouse. Aaron sees this play out on a tv screen in a seekrit room in the house (very spy like, and scary, yo), goes out to lecture Lilly on how he should treat his son and next thing you know, BAM, Lilly's dead.
Of course, this theory doesn't explain why the Kanes covered up the murder (just to save Duncan's ass of being covered in blood?), how Lilly was discovered at home, and is a bit on the wild side. But if there was some truth to Aaron-murdering-Lilly thing, then it was captured on camera and there's a tape of it lying around somewhere.
I'm still convinced that Lianne Mars had something to do with the murder, and they never explained why she went to see Jake Kane in the pilot.
More on the episode later.