The last sentence - as I've mentioned before, I don't really buy the 'inept investigation' schtick, not entirely, and not any more or less than any other police force. The scrutiny was immense from the get go and Leicestershire Police were entwined in the investigation very early on. Additionally, several outside agents also participated, so they were equally inept.
Did Amaral, et al (nice rhyming couplet there to add to my limerick database) go off on one, or were they following the evidence under intense global scrutiny? - Let's never forget the Murat whack-a-mole episode.
The failings of the investigation have no doubt been debated and discussed here ad nauseam (bit more latin for ya)
so I don't really want to dredge through all that. I doubt even the most hardened sceptic would deny that things could have been done better though.
My point was in relation to your claim about it having to be some perfectly executed crime, a claim I often see touted on the basis that there were no traces of an intruder. But it's very possible he just got lucky. And it's also very possible that there were traces, but the police didn't do a good enough job of highlighting or searching for them. How many forensic samples did they collect from the apartment during the initial sweep for example (excluding hairs)? What kind of tests did they carry out to check for the presence of any incapacitating agents? What CCTV did they collect from the surrounding area before it got wiped over? How can we be sure they don't in fact have forensics of the intruder, but just failed to assign them to anyone, like has apparently happened in the other 2 cases I cited? How can we be sure that forensic traces were left, but had been contaminated by their failure to preserve the integrity of the crime scene?
My argument is that people point to the implausibility of an intruder on the basis of what was NOT found. But they fail to question how intensive and professional the search for looking for those things actually was.