I've been tossing this around in my head...tell me what you all think. I'm just trying to make sense of this.
I have respectfully snipped the time line from Pu'f post of confirmed details.
My speculation's are in red.
This theory is an absolute accumulation of MOO!!! Pure speculation!!!!
IMHO I don't believe this was premeditated and I don't believe this involved WC.
3:01 PM - Mackenzie leaves the Academy of Hair Design where she works, gets in her car, and drives away.
MOO is after she left MC went to meet a friend, nothing sinister. I believe the meeting was prearranged in the day/days prior to her disappearing. I believe it was a close acquaintance. MOO is MC seemed like a very sweet and gentle young lady. So with that being said, maybe this person needed someone to talk to or maybe this person had a crisis and MC offered to be a shoulder to cry on. Pure Speculation.
3:40 PM - Mackenzie's phone data indicate that she is at/near the Riverfront Park boat ramp. While there, she sent a message to her boyfriend ("hey") and received a message from her boyfriend ("hey").
IMHO I don't think a 1 word text is odd at all. Personally, I have sent many one or two word texts to connect with loved ones and I've had the same done to me. (love you, hi, hey, miss you and so on). If MC was the person who sent the text IMHO if she felt uncomfortable with who she was with at the time she sent that text, she would have texted more. After awhile at the boat launch she leaves with this person willingly and goes to an unknown location. Nothing sinister. On the way, MC decides to make a quick stop to wash her car. After arriving at this unknown location, since she's isn't staying long, she leaves her purse in the car. At some point, maybe MC says something and it's taken wrong and this person is enraged and strikes out at MC and she is killed. ALL Pure Speculation.
5:42 PM- A cell tower bounces a signal off of MacKenzie's phone. This is the final activity on McKenzie's phone. Location has not been released by investigators.
IMHO I think MC was killed by the time her phone pinged. Maybe an unanswered call or text pinged the phone. I think this is where the panic sets in with the killer. (How am I going to cover this up?) This person needs to get rid of MC's car since it was parked in front of his/her house/apartment, hoping no one saw it. With the full intention of completely denying the meeting. (Oh no, haven't seen her, we had plans but she canceled earlier in the day/previous day). MOO is after she was killed, MC's body was placed somewhere near by. Maybe in a shed. ALL PURE SPECULATION. Then the car was driven up PC and left out in the open. MOO is that PC is a huge distraction. ALL PURE SPECULATION, MY OPINION AND NOT BASED ON FACT.
While driving up PC he/she realizes they'll need a ride back down and contacts a trusted friend swearing them to secrecy and asks for a ride. Or, maybe the killer was able to walk as far as Lincoln Park undetected and got a ride there. Maybe he/she walked east and ended up closer to the Humane Society. Maybe he/she headed up Crawford and was picked up near the Wenatchee High School. ALL PURE SPECULATION NOT BASED ON FACT.
8:02 PM Residents report to Rivercom finding a 1997 red Pontiac Grand Prix in Squilchuck area, 2395 Pitcher Canyon Road, parked near a cattle gate. LE uses the registration info on the car to Reid Cowell as the owner, who confirms that his daughter has been out past curfew.
MOO is this person went about their business as usual that evening, being sure to act as normal as possible, knowing they would be contacted by LE. MOO is in the next day or two MC was moved to CB where she was placed by the river to be disposed of. MOO this person knew his/her whereabouts would be examined closely so he/she made sure not be unaccounted for very long at any time after MC disappeared. While in CB on the river bed, he/she wasn't able to complete what was planned, maybe this person vomited. Since this person didn't have a lot of time, MC was covered with some brush. The killer planned on returning as soon as possible as soon as he/she could slip away from the eyes of friends and family. I don't believe this person intended on using a boat, I believe this person wanted to dispose of her right there on the rivers edge.
IMHO, I believe MC's killer acted alone and if anyone else does know anything, all they know is that the killer wasn't where he/she said they were during the crucial time period, and they were asked not to say anything.
ALL THE WORDS IN RED ARE PURE SPECULATION NOT BASED ON ANY FACTS.