MOO, follows:
I do not believe LE is close to solving this case. They might be closer than they were two weeks ago, i.e., they might know the COD and might even have guessed correctly which items were used in the attack, but now ... I think they've reached a dead end.
I think LE started out believing it was a 'close to home' murder, that the perp is someone with whom MC was quite familiar, i.e. family, relative, boyfriend, best friend, etc. but the expected 'perp profile' doesn't seem to be holding true in this case.
LE might be second guessing their original 'educated assumption' of a 'close to home' perp.
What if the 'perp' simply was driving along and MC accidently cut him off ... and Mr. A. B. Normal lost it?
No boyfriends, no Tacomas, no Spokanes, no premeditation, no boyfriends, no gangs ... just one pissed-off motorist who was cut-off one too many times that week.
Heck .. .that is as plausible as anything else discussed, eh?