I think the phone remains in the complex where Brian was last seen. Probably in his pocket.
I respectfully disagree & would argue that investigators are aware of phone data that indicates he made it out of the building, assuming Brian’s phone was on his person at the time of his disappearance.
*Brian’s phone was on around 1:55-1:58 AM when Brightan put her # in.
*At 2:00 when Clint & Meredith exited the bar, they did not see him. Meredith called Brian at 2:01 but the phone was off or out of service (I personally believe he turned it off to avoid Clint & Meredith who were supposed to give him a ride home, but it could’ve briefly been out of service if he was in an elevator or the construction area I suppose).
*If you argue that his phone was out of service because he entered the construction area, why did it come back on and communicate with cell phone towers until 2:11 AM (per Hurst)?
In my opinion, Brian turned his phone off briefly as he took an alternate exit and way home to avoid being seen by Clint & Meredith as he exited the bar.
*Brian’s apartment was a 1/2 mile from the UTS. It’s a 10 minute walk. I think he kept his phone on while he took Pearl Alley home, perhaps for light or safety. If he made it home, he then turned it off again after 2:11 AM.
*Hurst wouldn’t say what kind of retroactive pinging data they have for that weekend, but my guess is that it was on & pinging. As
@MysteryMaven recounted, Hurst says something like “the phone did not connect to any towers the morning after Brian went missing.” He is vague. He just says “morning.” Think about that. What are we being told without being told?
*When they put the pinging service on the phone on Monday, they got pings. Remember… a phone has to be turned on and powered up to ping. Any of you who now use Life 360 know if someone’s power is low, they can’t be tracked. You think that’s going to happen buried in concrete or in Brian’s pocket behind drywall… for days?
*We can debate whether or not at this point Brian had his phone & was moving with it or, if something nefarious happened, someone else had his phone. However, it was moving in a westward direction. Think about back then before GPS how many pings investigators had to have gotten to be able to triangulate a signal. Not just 1.
*Hurst reports pings at Kenny Rd & Lane Ave, triangulation at Scioto Darby Creek are, and less specifically refers to pings in the “Westside/Westbelt area” and “a few after that.” Each is further west from the next. A stationary phone that is powered on for days is not going to progressively jump farther west to a tower in a sequential motion. That phone was in a car on the highway. Look at a map & you will see 315 S to (briefly 70 W as
@Valiant said) to 270 N hits all the marks.
MOO