@Scoops. Thank you for your patience. I'd love to make a spreadsheet with all of the confirmed facts of this case. It seems like there are so many accounts that completely contradict each other. Renner's blog implies that Fred was evasive. It says that he didn't meet with police until two days after the disappearance, and wasn't formally interviewed for another two years. After reading your response and doing some searching, it does appear that Fred Murray called police immediately, yet didn't arrive on the scene for another 48 hours. Lol, I hate to agree with you so much because I'm still not convinced by your suicide hypothesis, but I admire your accuracy and dedication to the facts. In any event, it does seem that Fred pushed the police to investigate this as a suicide for the first 48 hours, and then did a 180 to push the creep theory. I can think of two reasons why he would do this, one is what you've already mentioned... he assumed she went there to commit suicide but was willing to change his story as needed to keep attention on the case... and the other reason, well I'm not allowed to discuss that here.
Fred didn't find out about his daughter going missing until late in the evening of Feb 10. this is confirmed. Police weren't really doing a whole lot at this point concerning the investigation, but they had made an attempt to get a hold of Fred and ended up getting in touch with Fred's kids back in Massachusetts.
Fred's kids attempted on their own to find out more information, but they kept getting the run around as they would call a police department in New Hampshire for help only to be directed back to UMASS police since Maura was a student at UMASS.
Fred wasn't anywhere near his home residence and hadn't been for months as he was living out of an extended suites hotel in Connecticut at the time.
Fred drove through the night and arrived to the accident location before dawn on Feb 11.
Family members were doing interviews with police right away once they all got the accident location and set up a "command post" at a nearby motel.
Through accounts of Sharon Rausch among others, police were conducting pretty intense interviews with, family members of the Murrays to include Billy and Kathleen.
The suicide narrative was not the cops, it was introduced to them by Fred Murray, they didn't know Maura from the next person.
Fred very early on (when being interviewed on TV) was making direct pleas to his daughter to please come back, it wasn't too late, they could work out whatever was wrong.
Not long after those initial days of searching for Maura, the family's public stance began to change.
In interviews with the media, the family were blaming the police for trying to force a suicide narrative about Maura, so they wouldn't have to account for a serial killer roaming the streets of their local area.
Trust was snapped all around and yes Family began to be less cooperative with police as I understand it (as far as interviews go).
The rag in the tailpipe was just one of the things that interested police concerning a possible suicide connection. They also honed in on the Tylenol PM and alcohol and the book Not Without Peril.
So the logical chain of events would show IMO, that police confronted Fred at some point about the rag in the tailpipe that they discovered and by that time, IMO, Fred didn't want it to have any link to his original suicide theory he introduced to police, so he quickly explained it away.