Well, based on the scanty reports online about his whereabouts - it seems like it could be possible. It was reported that he traveled between FL and MO and possibly even broader - like coast to coast. His long-time girlfriend and kids were in FL, but he was most recently in MO.
I stumbled upon Holly's story by accident last night and it gave me chills - the man was described as 5 foot 8 to 6 feet tall and 200 pounds - Adam does fit that description - he was just shy of 6 feet, and when I knew him, his weight was always 180-200.
If nothing else, it seems like exploring his whereabouts at that time would be prudent. I emailed two different police departments involved with Adam's case and Holly's cases and got a "not authorized to release that information" so I don't really know if that means they have made a connection or not.
I feel like this case is screaming for attention - maybe I am just too close to it. But, I really feel that if this story went national, a flood of information about Adam would surface and pieces would start falling into place. Just because he is dead does not mean that the families don't deserve some sense that justice was served.