Personally, I think it would be naive to believe otherwise. If that were the full extent of all they had, their actions over the last 20 months would be completely unjustified.
The BKA aren't going to just lay out all their evidence for public debate. They've only publicised certain select bits of evidence in order for the appeal to get taken seriously IMO, no more, no less. BKA said right from the start, they did not take the decision to go public "lightly". They would have been more than aware of the ripples this would generate.
CB isn't going anywhere, the BKA have no real time constraints and I think people possibly read too much into the fact there's still no charge 20 months on from the appeal. In theory, they could still find the crucial 683 caller for example, so why rush to charge? In my view, this all seems like part of a long term strategy and any charge over MM would likely come after he's been tried for the other 3 offences in Portugal currently being touted anyway.
I don't believe for one moment though that all they have is a phone ping and a 'profile that fits'. When you consider all the actions the BKA have taken, I think it's important to ask - Why?
Why would the BKA involve themselves in this hot potato of a case, if they had no real evidence other than what we've been told about so far?
Why put themselves in the spotlight of a media frenzy and risk ridicule and libel suits by publicly proclaiming CB's guilt if they had nothing of any real substance to back it up?
Why would they spend over 4 years investigating this lead if all they have got is hearsay and a phone ping which doesn't even place the phone at the crime scene or during the crime window?
Why would they spend all this money and waste their limited resources on a case where the victim isn't German, the crime took place in another country and they have no responsibility to investigate it?
Why wouldn't they just hand over the evidence they've got to PJ and SY and let them deal with it unless they were pretty confident they could get a conviction?
Why have they taken this unprecedented approach of publicly accusing someone of murder without charging them, in a country where privacy laws are extremely strict and further...
...Why would that approach have been sanctioned at a higher level if there wasn't already strong indicative evidence to warrant such a bold action?
Any claims that they are just on some tenuous fishing expedition... or they are fitting up a patsy... or that they have no real evidence... or that they are just plain incompetent..... none of these stand up to any kind of proper logic or scrutiny when considering the above questions.
IMO, they had enough evidence to convince them of CB's guilt but not quite enough to assure a conviction. With no forensics linking him to the crime scene and no body, you can see why they might have a problem in that regard. But they certainly have a lot more than what we know about so far IMO.
And from HCW's comments in October, he says they do "now" have enough to charge CB. I've seen nothing so far to contradict that not being the case and therefore, they must have some pretty strong evidence to back up their claims. JMO