So reading the affidavit again, Grandmother Rose and Julia's maternal Aunt Jody said Julia told them she was scheduled to clean Monday at 6:00 am. KT and JN (twin) said JT left the family home around 7:30 am Monday to probably pick up a co-worker and go to a clean job.
If Julia was going to the clean job alone Monday, wouldn't she need company cleaning supplies? The place being cleaned may have some supplies, but isn't it part of the service for the cleaning company to bring it's own supplies?
Speculation: Could JT have made arrangements with Julia to meet at the apartment Sunday night to drop off supplies or to show her how the vacuum works etc... And give more detailed instructions of what was to be cleaned? I could see JT doing this because businesses that hire professionals to clean expect a quality job and may have specific instructions for its vendors. JT may have done a demo in Julia's room to show how the client wanted the rugs vacuumed or something. JT would have manipulated the demo to get the key.
Could JT have grabbed the key to the main door when Julia wasn't looking and returned after 12:00pm? This way KT and JN (twin) may not have missed JT. Since it was a risk to be away from the family home. JT could've locked up at Julia's place returned to Monroe and went back to Ypsi. in the AM to tidy up.
KT did say she remembered getting up in the night to use the restroom, but JT might know KT's sleeping patterns better than she knows, and most people do fall asleep the first time for a good 4 to 4 1/2 hours, before waking, getting up, and then falling back to sleep.
Still this wouldn't explain the loud TV the roommate heard, stopping in on Sunday night, which may or may not be relevant to Julia's TOD. But it explains the phone call between JT and Julia on December 9th, keeps the family alibi intact, keeps Julia as the one sending all texts Sunday night. However, it doesn't explain why Julia (or someone) texting her roommate asking when she would be returning to the apartment. Maybe she was just curious to know if she would be entering the apartment late. Or Julia wanted to talk with her about something.