In my opinion, I don't think the face in the still frame is Sami. She is in the back. As the front passenger does a hair flip with her right hand, Sami is simultaneously closing the car door with what would have probably been her right hand. It is impossible, I believe, for these two things to happen at the same time. The image is of somebody in the front seat, otherwise the glare of the light on the face would not have been visible. In full speed it seems more obvious to me. It is just a coincidence he is riding around the very next night at 3AM in the same area with a female passenger while there is blood all over the inside of the car???
I have looked at the enhanced pictures and one time, I think it is another person, the next I do not think another person can be seen. I am undecided, which is not unusual if I can view things two ways with the facts presented thus far in a case. Some points though that I can think of where I can make the argument that would fit with another person being a possibility or that work with it:
My first thought on reading the first facts of this case was that this could not be an easy thing to do by just one person, he had to drive and she was unreachable in the back seat while he is driving. (I can also argue this one in the other direction though).
It may vary but we use taxis quite often and where I was happy with the city owned taxi service, the person I am generally with when we have need for a taxi likes Uber now or did anyhow (although they have failed us recently so that may change). In all cases, she jumps in the front and I never knew a person could do this, however, I am older and she is younger and again, maybe it differs where we are located. I now have noticed most people do. One could ask her SJ's friends if they cabbed together whether one would jump in the front and whether SJ ever did with them or on her own that they have seen. One reason she did not could definitely be that someone was already in the front.
I very much agree with your thought above and have had the same thought since they shared the fact that blood was seen in the car. Yet he was driving around with a light interior with a woman, caring less if she saw the blood and she apparently cared less either. In the wee hours of the morning the next day, AGAIN, and in the same area. This fits, like maybe it was a usual thing? Robbery? SA?--it wouldn't be the first time a woman helped a man get someone in a vehicle by being "present"...
The woman the next day who was with him when he was apprehended I doubt was a "pickup" as she was said to be "cooperating". That sounds more like someone he knew and who was possibly involved. They likely had to acknowledge her as in the car upon arrest as people probably noticed the fleeing and subsequent arrest and may have reasons they have not said with regard to the abduction.
Not everything has been shared yet, and generally never is, this is a pretty fresh investigation. They have not shared the weapon used and may not be acknowledging another passenger when SJ was picked up for various reasons. They may be still confirming it and while they may have determined there was someone in the car, they may not be sure they can prove who. For me, when I do think I see a person, I cannot tell whether the person is female or male for instance. Yet I am not skilled at enhancing pics.
We also do not even know when she was killed. There were quite a few hours between her getting into the car and the missing report. The woman, if there was one, could live where the phone pinged even. While it could have pinged just because the car was passing a home, it stands out to me that her friends say they tracked it to a home on the street. They could have pulled right into a garage with the Chevy so no passerbys could see what happened next which I would rather not think about. Later put into the trunk and out to the 70 mile away location.
I think it is possible as well that by the time the police pulled him over that beyond just the car matching, they may have even had an inkling of who they might possibly be looking for based on the woman (if they knew about her and if she was for instance a gf), where she lived and the remarks about the location SJ was found and that someone would have had to have known the area to dispose of SJ there. Possibly...
SJ could have even met the two while out that night and recognized them (or if it was just him that could still have happened.
I can also make it it work with him being alone and at times, I do not think what I see in the pics are a person...
At the moment though, I am leaning towards another person being involved whether at the time of abduction or shortly after. The fact the woman would be in his car the next day with him fully aware there was blood in it just is beyond my believing he would not care if she noticed, unless she knew already... Hence cooperation...?
It shouldn't be the case, but I would probably be more comfortable if there was a woman with a man who pulled up... And if I even possibly met them earlier or even just recognized them, even more so...
I will certainly think twice now...