After reading a couple days here, media reports and the FB page - I'm trying to parse out the known information seeking possibilities. WS seems a better choice for "thinking outloud" than the FB page - in respect for family.
First, is Robert missing due to (A.) a decision he made, Or (B) medically related crisis, OR (c) foul play?
A). Was he dealing with an issue his family/friends are unaware of (health, financial, a relationship, legal or something else that caused him to decide to leave on his own? I've read the reports that all was fine at home and that he would never leave them like this. But as we know from past cases.... it can and does happen. Seems the best way to determine if this reason is at play is to delve into his phone, computer and financial records. Go through his paperwork, any locked drawers, closets, etc.
B). Could he have had a medical crisis (physical or emotional) and be at some facility? He reportedly had no ID with him and he may not be able to tell them who he is. It seems that if this occurred while he was with his car, any responders would have determined his identity from vehicle records.
C). Foul play is the reason he is missing. Based on reports from family that it is so very out of character for him to take off, this seems like a significant possibility. If ex., a stranger jacking the car, seems they would have kept the vehicle for a period of time or taken it to a seedy chop shop. Or if Robert was forced to drive, there would have been some scene at the train station where car was left. In addition, they would probably have occurred on his way home, since his car was left relatively close to home and not in the city.
I am leaning toward A or C. Any comments or feedback is welcome. Prayers he will be located soon and for his family.