I don’t know that they can prove it was exactly at 8:49, you can’t get to the exact minute of death with the body temperature, you can get into a range and that time is in the range. I think the 8:49 is based off of various phone activities or lack there of and activity they are pretty certain is credited to the killer. Pretty certain they have boxed it in to a 3-5 minute window.
Basked on Alex’s own admissions and all data points, he was on the property. The whole, i was taking a nap thing, has totally fallen to the wayside, that was his excuse early on. The nap thing doesn’t make sense now that he has had to fess up he was at the kennels. There was no time for a nap, He left the property with in about 15 minutes or so of killing them. So now he says he left the kennels at approximately 8:48 - 8:49 and came back to the house, sat on the couch and maybe dozed off and was scurrying around less than 15 minutes later with 287 steps and multiple phone calls and leaving the house at 9:04 i think.
I think he hightailed it back to the house with the guns, wrapped them in a rain coat, stripped naked and stashed it all in his suburban. Showers in the house quickly and is running around franticly calling people, calls Maggie a few times trying to establish an alibi.
The weird thing about calling Maggie is it doesn’t make sense. He was just with her (now that he‘s admitted to being at the kennels) a few minutes prior and he is supposedly calling her to let her know he was leaving. Called her twice (and of course she doesn’t answer b/c she is dead). But instead of driving out that way to say I am leaving after calling twice and getting no answer, he doesn’t do that. None of that really makes logical sense. If the plan all along was to go to Alameda you would tell her when you last saw her like 15 minutes ago, hey I am going to leave shortly to go see dad. If you called twice and couldn’t talk, wouldn’t you drive literally 60 seconds or less out of your way to say you were leaving.
His whole story is crumbing when put under scrutiny and you ask yourself would a normal person act this way, and of course no one would. Only someone who had murdered their wife and son and was trying to figure out what to do.