I've been doing the same - going over this timeline all in one place - and three timeframes interest me:
AFTER he left the Albertsons in Clarkston, WA at 1:04, the PCA does not address the time from 1:04 to 5:32 pm.
- So what was he doing during that timeframe after shopping at Albertsons? Did he buy something there in which he could conceal the knife for burying it somewhere - a cylindrical cookie tin, or Pringle container, or a holiday cylinder or long narrow box for gifting wine or liquor?
Then, from 5:23 to 5:36 pm, the phone connects to the network in Johnson, ID (I think it must actually be Johnson, WA - north of Clarkston, WA - because I cannot find a Johnson, ID).
Then, from 5:36 until 8:30, the phone is disconnected from the network.
- These would be hours AFTER daylight, so if he was burying evidence or placing it somewhere outdoors, he would have cover of darkness.
So, did he temporarily stash evidence after driving south after the murders (at which time he discovered the missing sheath - which he may have hoped to recover when returning to King Rd from 9 to 9:30 am)? And then, later return to grab the evidence for more permanent disposal and/or stashing?
I tend to think he'd want to hold onto that knife or at least stash it somewhere that he knows he can return to later, to recover it.